TECHNICAL REPORT Submitted to EFSA Preparatory Work for The

EN-181

TECHNICAL REPORT submitted to EFSA

Preparatory work for the future development of animal based measures for assessing the welfare of pigs1

Report 2: Preparatory work for the future development of animal based measures for assessing the welfare of weaned, growing and fattening pigs including aspects related to space allowance, floor types, tail biting and need for tail docking

Prepared by Hans Spoolder2, Marc Bracke2, Christine Mueller-Graf3, Sandra Edwards4

2 Wageningen UR Livestock Research, PO box 65, 8200 AB, Lelystad, The Netherlands

3 Federal Institute for Risk Assessment (BfR) Head of Unit Epidemiology, Biometry and Mathematical Modelling Department Scientific Services, Alt-Marienfelde 17-21, D-12277 Berlin, Germany

4 Newcastle University, School of Agriculture, Food and Rural Development Agriculture Building Newcastle upon Tyne, NE1 7RU, UK

Abstract

The EFSA Animal Health and Welfare panel is requested to develop several scientific opinions concerning animal based measures to assess the welfare of livestock animals. Before this work can start, it is important that conclusions and recommendations of the EFSA scientific opinions are up

1 (Question No EFSA-Q-2011-00879)

Accepted for Publication on 05 July 2011

The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors. European Food Safety Authority - Largo N. Palli 5/a, I - 43121 Parma Tel: (+39) 0521 036 200 • Fax: (+39) 0521 036 0200 • www.efsa.europa.eu

Preparatory work for pig welfare indicators – Report 2

to date. The main objective of this report is to review the pig welfare literature to identify gaps and potential areas to strengthen or amend three recent pig welfare opinions: one on the welfare of Fattening pigs (2007), another on Space allowances and floor design (2005) and a final one on Tail biting (2007). The literature review was done by a group of authors and reviewers, under the supervision of an editorial team. Over 200 new scientific literature references are quoted. Regarding the first opinion, this review presents 11 new or revised conclusions. In addition it suggests several new recommendations. These include suggestions for maximum noise levels and ammonia levels, and minimum light duration. Furthermore, attention is drawn to the need of pigs to cool themselves when ambient temperature is high. Finally, the recommendations also emphasise the need to further study the relationship between space allowance and negative social behaviours. Regarding the second opinion, it draws 5 conclusions. The recommendations predominantly confirm those in the original opinion, but also emphasise the need for a well maintained substrate to reduce leg problems and gastric ulcers. For the third opinion, 10 new conclusions are added. The recommendations include the monitoring of tail length at the slaughter line, and the use of new management and housing information to avoid the need for tail docking. It also suggests that an intact curly tail can be regarded as the single most important welfare indicator in finishing pigs.

Summary The EFSA Animal Health and Welfare panel is requested to develop several scientific opinions concerning animal based measures to assess the welfare of livestock. The main background documents for these mandates are the EFSA Scientific Opinions on the welfare of livestock and the Welfare Quality® assessment protocols. EFSA has issued in the past the 5 scientific opinions on different aspects related to the welfare of pig. Three of these are: i) Animal health and welfare in fattening pigs in relation to housing and husbandry (2007); ii) The welfare of weaners and rearing pigs: effects of different space allowances and floor (2005) and iii) The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems (2007). The terms of reference (ToRs) of the Commission mandates on animal based measures to assess the welfare of livestock animals suggest that such measures could be used to check whether the recommendations listed in the EFSA scientific opinions are fulfilled or not. It is therefore important that conclusions and recommendations of the EFSA scientific opinions are up to date.

The 5 scientific opinions are evaluated in two reports. The main objective of both reports is to present preparatory work for the future mandate on animal based measures for assessing pig welfare. It is a review of the literature provided in the opinions in order to identify gaps and potential areas to strengthen or amend the conclusions and recommendations of such opinions. It also aims to identify hazards that may be revised by the AHAW Panel in light of the newly available scientific evidence. The present report addresses the three opinions referred to above, presented here as sub-reports C, D and E, respectively.

The editors of the two reports used a step wise iterative approach in which they involved experts from different research institutes. An initial literature search resulted in a large number of abstracts, of which more than 800 were read by the editorial team and analysed for statements relevant to the two reports. Authors were recruited and were sent one or more paragraphs with statements derived from the abstracts. They were asked to add their expertise, any missing references and statements, and to develop the statements into texts for each paragraph. The draft paragraph texts were then

Preparatory work for pig welfare indicators – Report 2

sent to „first reviewers‟. These reviewers received large chunks of each report (several paragraphs from several authors) and developed the texts further. They provided additional expertise or references. Subsequently, five „second reviewers‟ were asked to do the same as the first reviewers. In a final step the editorial team over-viewed the text and put together the list of recommendations and associated hazards, based on the original recommendations list of the original EFSA reports.

The literature searches conducted at the beginning of this project (for both Reports 1 and 2) resulted in 6435 unique references (for both reports). Databases searched included CAB Abstracts, Agricola and ISI Web of Knowledge (which included both the Science Citation Index Expanded (SCI-EXPANDED) and the Conference Proceedings Citation Index- Science (CPCI-S) databases). General searches were conducted on pig welfare as of (and including) 2007 using the key words pig*, sow*, boar*, welfare, well-being, behav* and stress. Specific searches were conducted on space and floors (as of 2005) using the key words floor*, space and castr*.

For the present report a total of over 200 scientific publications were used to formulate additional conclusions and recommendations to the original opinions.

Conclusions for sub-report C on “Animal health and welfare in fattening pigs in relation to housing and husbandry” include: i) genetic traits of fearfulness and aggression have been identified and could be incorporated in practical breeding programmes to improve welfare, ii) all new data reinforce the importance of providing suitable enrichment materials to allow expression of species relevant behaviours and reduce risk of injurious biting, iii) destructibility, hygiene and novelty are key elements of suitable enrichment, iv) provision of cooling facilities for pigs are important in any situation of increased ambient temperature or endogenous heat production, v) Ammonia levels of >20ppm have adverse effects on pig physiology and behaviour, vi) There is a high prevalence of locomotory disorders on many farms which should be addressed through genetic and environmental improvement.

Recommendations for sub-report C include: i) since pigs have limited abilities to loose heat (they cannot sweat), pigs should be allowed to seek cooling when overheated, not only in case of elevated ambient temperatures, but also in cases of elevated activity, fever and high metabolism, ii) ammonia levels in pig housing should not exceed 20ppm, iii) noise levels in pig housing should be <80dB, iv) although the ability of pigs to discriminate between small visual cues at light intensities from 12 to 80 lux does not appear to change, a light intensity of >80 lux during activity periods reduces aggression compared to 40 lux. A minimum light period of 14h/day should be provided where artificial light is used, v) further research is needed to specify in more detail the effects of reduced space allowances on negative social behaviours, as well as the interaction between space allowance and enrichment, so as to identify the extent to which these factors can act as substitutes for each other.

Conclusions for sub-report D on “The welfare of weaners and rearing pigs: effects of different space allowances and floor” include: i) the allometric approach appears valid for pigs over a wide weight range, ii) behavioural measures suggest a higher optimum k value (0.037-0.039) than production measures (0.032-0.035), iii) the amount of space needed by an individual appears independent of group size, iv) walking safety and comfort is impaired by soiled floors, v) the effects of floor type on health are equivocal, with further evidence that solid floors are better for respiratory disease but detrimental to enteric and endoparasitic infections. The original recommendations of sub-report C

Preparatory work for pig welfare indicators – Report 2

are supported by the new data, but also include that a well maintained substrate such as straw should be used to reduce leg problems and gastric lesions.

Conclusions for sub-report D on “The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems” include: i) tail and ear lesions are indicative of reduced welfare (now and/or in the past). They can be detected fairly easily, even at the slaughterhouse. Healed lesions should be included in the observations, ii) while lack of enrichment is a main reason for such lesions, also a range of other factors may be involved e.g. reduced health, thermal inadequacies, problems with feed and water, etc.). All of these are associated with reduced welfare, iii) use of group selection as a breeding strategy has the potential to reduce genetic predisposition to tail bite, iv) reliable behavioural signs of an impending tail biting outbreak have been identified and can be used to take precautionary measures, v) tail and ear biting behaviour may be treated with enhanced enrichment (e.g. ample long straw provided fresh twice daily) throughout the pig‟s life. However, other risk factors (stocking density, ventilation, feed, ...) should be investigated or audited too, vi) research to date indicates that while toys may show some reduction in tail biting, especially when they have destructible components, natural substrates such as straw or compost seem to be necessary to reduce biting problems to acceptable levels in problem pens. Recommendations for sub-report D include: i) the wealth of information on how to reduce the risk of tail biting (such as providing suitable enrichment, ensuring a good thermal environment and appropriate feeding) without docking pig tails, should be used to underpin the importance of preventative measures, ii) monitoring at slaughter should include also tail length (in addition to tail lesions) as well as ear shape (missing parts of the ears) and biting wounds on flanks and legs, iii) an intact curly tail may well be the single most important animal-based welfare indicator for weaned, growing and finishing pigs (at herd level). In addition, it stands for high-quality management and respect for the integrity of the pig.

The hazards associated with the recommendations were presented for each sub-report. Overall, no new hazards were identified, although the evidence for many existing hazards was strengthened.

Key words: Pig welfare, fattening pig, tail biting, swine housing

Preparatory work for pig welfare indicators – Report 2

Table of Contents Abstract ...... 1 Summary ...... 2 Table of Contents ...... 5 Background ...... 9 Terms of reference ...... 9 Acknowledgements ...... 11 Introduction and Objectives...... 12 Materials and Methods ...... 13 1. Reviewer consultation...... 13 2. Literature searches ...... 14 References ...... 16 3. Sub-report C: update of the underlying report on adult pigs and unweaned piglets...... 18 3.1. Current production systems for fattening pigs in the EU (C.6.) ...... 18 3.2. Factors affecting pig welfare (C.7.) ...... 19 3.2.1. Pig genetics in relation to welfare (C.7.1.) ...... 20 3.2.1.1. Leg problems (C.7.1.1.) ...... 20 3.2.1.2. Cardiovascular problems (C.7.1.2.) ...... 20 3.2.1.3. Social behaviour and fearfulness (C.7.1.3.) ...... 21 3.2.1.4. Disease resistance (C.7.1.4.) ...... 21 3.3. Light inadequacy and noise (C.7.2.)...... 21 3.4. Ability to rest and sleep (C.7.3.) ...... 22 3.5. Ability to exercise (C.7.4.) ...... 23 3.6. Food and water in relation to pig welfare (C.7.5.) ...... 23 3.6.1. Effects of water supply (C.7.5.1.) ...... 24 3.6.2. Liquid feeding (C.7.5.2.) ...... 25 3.6.3. Lack of food and food restriction (C.7.5.3.) ...... 25 3.6.4. Lack or excess of specific nutrients (C.7.5.4.) ...... 26 3.6.5. Undesirable compounds in feedstuffs (C.7.5.5.) ...... 26 3.6.6. Benefits of specific foods - including feed additives (C.7.5.6.) ...... 26 3.7. Ability to explore (C.7.6.) ...... 27 3.8. Ability to have proper social interaction (C.7.7.) ...... 30 3.8.1. Lack of maternal contact (C.7.7.1.) ...... 30 3.8.2. Contact with other pigs (C.7.7.2.) ...... 31 3.8.2.1. Mixing of unacquainted pigs (C.7.7.2.1.) ...... 31 3.8.2.2. Group size (C.7.7.2.2.) ...... 32 3.8.2.3. Space allowance and access to resources (C.7.7.2.3.) ...... 32 3.9. Ability to avoid fear - including noise (C.7.8.) ...... 33 3.10. Ability to groom (C.7.9.) ...... 34 3.11. Thermal inadequacy - including noxious gases (C.7.10.) ...... 34 3.12. Humidity (C.7.11.) ...... 35 3.13. Respiratory disorders (C.7.12.) ...... 35 3.13.1. Air quality (C.7.12.1.) ...... 37 3.14. Gut disorders (C.7.13.) ...... 37 3.14.1. Postweaning diarrhoea (C.7.13.1.) ...... 37 3.14.2. Diarrhoea during finishing period (C.7.13.2.) ...... 38 3.14.3. Gastric ulcers (C.7.13.3.) ...... 38 3.15. Production related and other diseases - and use of growth promotors (C.7.14.) ...... 38 3.15.1. Injuries - and pain and leg problems (C.7.15.) ...... 40 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3.16. Food Safety related aspects (C.8.) ...... 40 Conclusions and Recommendations ...... 41 References for sub-report C ...... 47 4. Sub-report D: update of the underlying report on the effects of different space allowances and floor 61 4.1. The needs and functioning of pigs, in particular in relation to effects of flooring and space allowance (D.6.) ...... 61 4.1.1. The needs of pigs in relation to the space in which they live (D.6.1.) ...... 61 4.1.2. Describing space allowance (D.6.2.)...... 61 4.1.2.1. Physical dimensions of the animal (body space) (D.6.2.1.) ...... 61 4.1.2.2. Activity space (D.6.2.2.) ...... 62 4.1.2.3. Social space (D.6.2.3.) ...... 62 4.1.2.4. Group (and pig size) properties (D.6.2.4.) ...... 62 4.1.3. Foot size and biomechanical properties (D.6.3.) ...... 62 4.2. Current housing systems - in relation to space and floors (D.7.) ...... 62 4.3. Types of flooring used in pig production (D.8.) ...... 62 4.4. Effects of space allowance (D.9.) ...... 62 4.4.1. Effects of space allowance on air quality and its consequences (D.9.1.) ...... 62 4.4.2. Effects of space allowance on mobility and injuries (D.9.2.) ...... 62 4.4.3. Effect of space allowance on disease (D.9.3.) ...... 63 4.4.3.1. General introduction (D.9.3.1.) ...... 63 4.4.3.2. Infectious diseases of significant importance (D.9.3.2.) ...... 63 4.4.3.3. Enzootic diseases (D.9.3.3.) ...... 63 4.4.3.4. Non-infectious diseases (D.9.3.4.) ...... 63 4.4.4. Provision for other needs (D.9.4.) ...... 63 4.4.4.1. Space utilisation (D.9.4.1.) ...... 63 4.4.4.2. Activity space (D.9.4.2.) ...... 64 4.4.4.3. Interaction space and aggression (D.9.4.3.) ...... 64 4.4.4.4. Effects of space allowance on performance and adrenal responses (D.9.4.4.) ...... 65 4.4.4.5. Exploration and manipulation - tail injuries (D.9.4.5.) ...... 65 4.4.5. Effect of space allowance on the carcass and food safety (D.9.5.) ...... 66 4.4.5.1. Introduction (D.9.5.1.) ...... 66 4.4.5.2. Space allowance and carcass composition (D.9.5.2.) ...... 66 4.4.5.3. Space allowance and pig meat safety (D.9.5.3.) ...... 66 4.5. Effects of flooring (D.10.) ...... 66 4.5.1. Effects of flooring on air quality and its consequences (D.10.1.) ...... 66 4.5.2. Effects of flooring on mobility and injuries (D.10.2.) ...... 67 4.5.2.1. Flooring and mobility (D.10.2.1.)...... 67 4.5.2.2. Flooring and injury in weaners (D.10.2.2.) ...... 67 4.5.2.3. Flooring and injury in Grower/Finisher pigs (D.10.2.3.) ...... 67 4.5.3. The effect of floor type on disease (D.10.3.) ...... 68 4.5.3.1. General Introduction (D.10.3.1.) ...... 68 4.5.3.2. Infectious diseases of significant importance (D.10.3.2.) ...... 68 4.5.3.3. Enzootic Enteric disorders including internal parasites (D.10.3.3.) ...... 69 4.5.3.4. Respiratory disorders (D.10.3.4.) ...... 69 4.5.3.5. Effects of flooring on other health problems (D.10.3.5.) ...... 69 4.5.4. Provision for other needs (D.10.4.) ...... 69 4.5.4.1. Space utilisation (D.10.4.1.) ...... 69 4.5.4.2. Activity space (D.10.4.2.) ...... 69 4.5.4.3. Effects of temperature (D.10.4.3.)...... 70

Preparatory work for pig welfare indicators – Report 2

4.5.4.4. Effects of the amount of solid versus slatted flooring on behaviour (D.10.4.4.) ...... 70 4.5.4.5. Effects of flooring on maintenance and stress (D.10.4.5.) ...... 70 4.5.4.6. Flooring and performance in weaners (D.10.4.6.) ...... 70 4.5.4.7. Flooring and performance in finishing pigs (D.10.4.7.) ...... 70 4.5.4.8. Floor type and stress physiology in pigs (D.10.4.8.) ...... 70 4.5.4.9. Exploration and manipulation (tail injuries) (D.10.4.9.) ...... 70 4.5.5. The effect of flooring on the carcass and food safety (D.10.5.) ...... 71 Conclusions and Recommendations ...... 71 References for sub-report D ...... 78 5. Sub-report E: update of the underlying report on the risks associated with tail biting in pigs and possible means to reduce the need for tail docking ...... 85 5.1. Current production systems for fattening pigs in the EU (E.2.) ...... 85 5.2. Introduction to tail biting issues (E.3.) ...... 85 5.2.1. Tail biting process (E.3.1.) ...... 85 5.3. E.4. Current situation on tail (and ear) biting ...... 85 5.3.1. Recorded Prevalence in EU (E.4.1.) ...... 85 5.4. Welfare and health aspects of tail biting (E.5.) ...... 86 5.4.1. Behaviour (frustration, biters/bites/victims) (E.5.1.) ...... 86 5.4.1.1. Injuries, infections and pain (E.5.1.1.) ...... 87 5.5. Current situation on tail docking (E.6.) ...... 87 5.5.1. Legislation (E.6.1.) ...... 87 5.5.2. Current practices (E.6.2.) ...... 87 5.6. Welfare and health consequences of tail docking (E.7.) ...... 88 5.7. Hazard identification for tail biting (E.8.) ...... 89 5.7.1. Animal characteristics (E.8.1.) ...... 89 5.7.1.1. Breed and genetics (E.8.1.1.) ...... 89 5.7.1.2. Gender (E.8.1.2.) ...... 89 5.7.1.3. Weight or age (E.8.1.3.) ...... 90 5.7.2. Rearing (E.8.2.) ...... 90 5.7.2.1. Early housing conditions (E.8.2.1.9) ...... 90 5.7.2.2. Weaning age (E.8.2.2.) ...... 91 5.7.3. Social environment (E.8.3.) ...... 91 5.7.3.1. Group size, space allowance and stocking density (E.8.3.1.) ...... 91 5.7.3.2. Other aspects of the social environment (E.8.3.2.) ...... 91 5.7.4. Herd size (E.8.4.) ...... 91 5.7.5. Flooring and substrates (E.8.5.) ...... 91 5.7.5.1. Floor type (E.8.5.1.) ...... 91 5.7.5.2. Enrichment (E.8.5.2.) ...... 91 5.7.5.3. Straw (E.8.5.2.1.) ...... 92 5.7.5.4. Rooting material – earth, peat, compost (E.8.5.2.2.) ...... 92 5.7.5.5. Hanging toys, footballs, etc. (E.8.5.2.3.) ...... 93 5.7.6. Diet and feeding (E.8.6.) ...... 93 5.7.6.1. Restricted level of feeding and high feeding competition (E.8.6.1.) ...... 93 5.7.6.2. Form of feed (E.8.6.2.) ...... 93 5.7.6.3. Minerals (E.8.6.3.) ...... 93 5.7.6.4. Protein and amino acids (E.8.6.4.) ...... 93 5.7.6.5. Fibre (E.8.6.5.) ...... 94 5.7.6.6. Specific raw materials (E.8.6.6.) ...... 94 5.7.6.7. Feed additives (E.8.6.7.) ...... 94 5.7.6.8. Sudden changes in feed (E.8.6.8.) ...... 94

Preparatory work for pig welfare indicators – Report 2

5.7.6.9. Water provision (E.8.6.9.) ...... 94 5.7.7. Health/disease (as „causal‟ factor) (E.8.7.) ...... 94 5.7.7.1. Growth retardation (E.8.7.1.) ...... 94 5.7.7.2. Disease (E.8.7.2.) ...... 94 5.7.7.3. Parasitism (E.8.7.3.) ...... 94 5.7.8. Climate and ventilation (E.8.8.) ...... 95 5.7.8.1. Time of year (E.8.8.1.) ...... 95 5.7.8.2. Heat stress (E.8.8.2.) ...... 95 5.7.8.3. Cold and draughts (E.8.8.3.) ...... 95 5.7.8.4. Air quality (E.8.8.4.) ...... 95 5.7.8.5. Ventilation type (E.8.8.5.)...... 95 5.7.8.6. Light (E.8.8.6.)...... 95 5.7.9. Tail docking as a control measure (E.8.9.) ...... 95 5.7.10. Presence of pig(s) with tail injury (E.8.10.)...... 96 5.8. Risk assessment approach (E.9.) ...... 96 5.9. Management of tail biting outbreaks (E.10.) ...... 96 5.10. Food safety considerations (E.11.) ...... 98 Conclusions and Recommendations ...... 98 References for sub-report E ...... 103

Preparatory work for pig welfare indicators – Report 2

Background The AHAW Panel is requested to develop several scientific opinions concerning animal based measures to assess the welfare of livestock animals. A first mandate on Dairy Cows has been received in June 2010. A second mandate to develop a scientific opinion on animal based measures for pigs is foreseen by the management plan. The main background documents for these mandates are the EFSA Scientific Opinions on the welfare of livestock animals and the Welfare Quality2 assessment protocols. EFSA has issued in the past the following scientific opinions on different aspects related to the welfare of pigs: i) Animal health and welfare aspects of different housing and husbandry systems for adult breeding boars, pregnant, farrowing sows and unweaned piglets (2007a); ii) Animal health and welfare in fattening pigs in relation to housing and husbandry (2007b); iii) The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems (2007c); iv) The welfare of weaners and rearing pigs: effects of different space allowances and floor (2005) and v) Welfare aspects of the castration of piglets (2004).

The terms of reference (ToRs) of the Commission mandates on animal based measures to assess the welfare of livestock animals suggest that such measures could be used to check whether the recommendations listed in the EFSA scientific opinions are fulfilled or not. It is therefore important that conclusions and recommendations of the EFSA scientific opinions are up to date.

The main objective of this procurement project is to carry out preparatory work for the future mandate on animal based measures for assessing pig welfare. A review of the literature provided in the scientific opinions in order to identify gaps and potential areas to strengthen or amend the conclusions and recommendations of such opinions is expected. In addition, the identification of hazards that may be revised by the AHAW Panel in light of the newly available scientific evidence is also foreseen.

In line with the specific pig populations, the preparatory work may be subdivided in two lots: i) preparatory work for the future development of animal based measures for assessing the welfare of sow, boar and piglet including aspects related to pig castration and ii) preparatory work for the future development of animal based measures for assessing the welfare of fattening pig including aspects related to tail biting.

The preparatory work, to be completed by March 2011, will help the AHAW panel to update the conclusions and recommendations of the previous EFSA‟s scientific opinions on pig welfare in order to develop the future mandate on animal based measures for the assessment of welfare of pigs.

Terms of reference The present procurement project will address the following two points: i) to review the literature provided in the scientific opinions in order to identify gaps and potential areas to strengthen or

2 Welfare Quality® Consortium, ASG Veehouderij BV, Lelystad, The Netherlands. Project co-financed by the European Commission, 6th Framework Programme.

Preparatory work for pig welfare indicators – Report 2

amend the conclusions and recommendations of such opinions; ii) to identify hazards that may be revised by the AHAW Panel in light of the newly available scientific evidence.

Preparatory work for pig welfare indicators – Report 2

Acknowledgements

This contract was awarded by EFSA to: Contractor: Animal Science Group (ASG), Wageningen UR Livestock Research, The Netherlands Contract title: Preparatory work for the future development of animal based measures for assessing the welfare of pigs Contract number: CT/EFSA/AHAW/2011/01

11 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Introduction and Objectives

INTRODUCTION The EFSA Animal Health and Welfare panel is requested to develop several scientific opinions concerning animal based measures to assess the welfare of livestock animals. A first mandate on Dairy Cows has been received in June 2010. A second mandate to develop a scientific opinion on animal based measures for pigs is foreseen by the management plan. The main background documents for these mandates are the EFSA Scientific Opinions on the welfare of livestock animals and the Welfare Quality® assessment protocols.

EFSA has issued in the past the following scientific opinions on different aspects related to the welfare of pigs: i) Animal health and welfare aspects of different housing and husbandry systems for adult breeding boars, pregnant, farrowing sows and unweaned piglets (2007a); ii) Animal health and welfare in fattening pigs in relation to housing and husbandry (2007b); iii) The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems (2007c); iv) The welfare of weaners and rearing pigs: effects of different space allowances and floor (2005) and v) Welfare aspects of the castration of piglets (2004).

OBJECTIVES The main objective of this report is to present preparatory work for the future mandate on animal based measures for assessing pig welfare. It is a review of the literature provided in the scientific opinions in order to identify gaps and potential areas to strengthen or amend the conclusions and recommendations of such opinions. In line with the specific pig populations, the results of this project for EFSA are presented in the following two reports:

Report 1: Preparatory work for the future development of animal based measures for assessing the welfare of sow, boar and piglet including aspects related to pig castration.

Report 2: Preparatory work for the future development of animal based measures for assessing the welfare of fattening pig including aspects related to tail biting.

The present document is Report 2. The specific objectives for Report 2 are as follows:

To review the literature provided in the previous EFSA scientific opinions:

12 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

c) Animal health and welfare in fattening pigs in relation to housing and husbandry (2007b); http://www.efsa.europa.eu/en/efsajournal/doc/564.pdf d) The welfare of weaners and rearing pigs: effects of different space allowances and floor (2005) http://www.efsa.europa.eu/en/efsajournal/doc/268.pdf e) The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems (2007c); http://www.efsa.europa.eu/en/efsajournal/doc/611.pdf in order to identify gaps and potential areas to strengthen or amend the conclusions and recommendations of such opinions;

To identify hazards that may be revised by the AHAW Panel in light of the newly available scientific evidence (i.e. identify hazards in scientific papers about floor and space allowance for pigs published after 2005 and scientific papers about fattening pig welfare published after 2007).

The focus of the report is on science-based knowledge that is important for decision makers, in particular scientific knowledge and advice (recommendations) that specifies how pig welfare may be monitored and improved in Europe in the (near) future, and that has become available after the publication of the underlying reports (or which revises them).

Materials and Methods

METHODS

1. Reviewer consultation The editors of this report used a step wise iterative approach in which they involved several experts from different research institutes. For this and the other report, the following steps were taken simultaneously.

Step 1

An initial literature search resulted in a large number of abstracts, of which more than 800 were read by the editorial team and analysed for statements relevant to the present report. The screening of literature is described in one of the paragraphs below. The statements derived from the abstracts were allocated to chapters presented in the original EFSA reports.

Step 2 Authors were recruited and they were sent one or more paragraphs with statements derived in Step 1. They were asked to add their expertise, any missing references and statements, and to develop the

13 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

statements into texts for each paragraph. A total of 20 co-authors contributed in this step of the process. They remained anonymous throughout this and the following steps.

Step 3 The draft paragraph texts were then sent to „first reviewers‟. These reviewers received large chunks of each report (several paragraphs from several authors) and developed the texts further. They provided additional expertise or references. They were also asked to check for „novelty value‟ (since original report). Altogether six „first reviewers‟ completed their work.

Step 4 Was similar to step 3, but included five „second reviewers‟. They were asked to do the same as the first reviewers.

Step 5 The editors then asked all authors and reviewers to have a final look at the sub-reports they contributed to, and suggest improvements. In addition, they were asked to contribute to the recommendations section of this report, and add their recommendations.

Step 6

In the final step the editorial team had their final look and put together the list of recommendations and associated hazards, based on the original recommendations list of the original EFSA reports.

2. Literature searches The literature searches conducted at the beginning of this project resulted in 6435 unique references (for both reports). Databases searched included CAB Abstracts, Agricola and ISI Web of Knowledge (which included both the Science Citation Index Expanded (SCI-EXPANDED) and the Conference Proceedings Citation Index- Science (CPCI-S) databases). General searches were conducted on pig welfare as of (and including) 2007 using the key words pig*, sow*, boar*, welfare, well-being, behav* and stress. Specific searches were conducted on castration (as of 2004) using the key words floor*, space and castr*.

Technical details of the general searches

CAB Abstracts [conducted 07-02-2011]: (((pig* or hog* or swine or sow* or boar*) and (((welfare or well-being or behav*) and health) or stress)).ab. and ("2007" or "2008" or "2009" or "2010" or "2011").yr.) not (pigeon* or "guinea pig" or piguvian).ab. [".ab" means "Abstract field"].

Agricola [conducted 07-02-2011]: (((pig* or hog* or swine or sow* or boar*) and (((welfare or well-being or behav*) and health) or stress)).ab. and ("2007" or "2008" or "2009" or "2010" or "2011").yr.) not (pigeon* or "guinea pig" or pigo*).ab. [".ab" means "Abstract field"].

ISI Web of Knowledge [conducted 09-02-2012]: Topic=((pig or pigs or piglet* or sow* or boar*) and animal*) AND Topic=(welfare or well-being or (behav* and health) or stress) NOT

14 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Topic=(pigeon* or "guinea pig*" or pigo*) AND Topic=(significant*), Timespan=2007-2011. Databases=SCI-EXPANDED, CPCI-S.

Specific searches (for „castration‟ Sub-report B)

CAB Abstracts [conducted 10-02-2011]: ((pig or pigs or piglet* or hogs or swine or sow or sows or boar*) and castr*).ab. and ("2004" or "2005" or "2006" or "2007" or "2008" or "2009" or "2010" or "2011").yr. [".ab" means "Abstract field"].

ISI Web of Knowledge (10-02-2011): Topic=(pig or pigs or piglet* or hogs or swine or sows or boar or boars) AND Topic=(castr*), Timespan=2004-2011. Databases=SCI-EXPANDED, CPCI-S.

Specific searches (for „health‟)

We initially found very few references to pig health in relation to welfare. So we added two other searches:

OvidMedline (((pig or pigs or piglet* or hogs or swine or sow* or boar*) and (health or disease) and (risk or odds)).ab. and ("2007" or "2008" or "2009" or "2010" or "2011").yr.) not (pigeon* or "guinea pig*" or pigo*).ab.

ISI web of Sci+Conf proceedings: Topic=(pig* or hog* or swine or sow* or boar*) AND Topic=(health or disease) NOT Topic=(pigeon* or "guinea pig*" or pigo*) Timespan=2007-2011. Databases=SCI-EXPANDED, CPCI-S. (restricted to vet sci)

15 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

References Bracke, M.B.M., Edwards, S.A., Engel, B., Buist, W.G., Algers, B., 2008a. Expert opinion as 'validation' of risk assessment applied to calf welfare. Acta Veterinaria Scandinavica 50. Moura, D.J., Silva, W.T., Naas, I.A., Tolon, Y.A., Lima, K.A.O., Vale, M.M., 2008. Real time computer stress monitoring of piglets using vocalization analysis. Computers and Electronics in Agriculture 64, 11-18. Mullan, S., Browne, W.J., Edwards, S.A., Butterworth, A., Whay, H.R., Main, D.C.J., 2009. The effect of sampling strategy on the estimated prevalence of welfare outcome measures on finishing pig farms. Applied Animal Behaviour Science 119, 39-48. Schön, P.C., Puppe, B., Tuchscherer, A., Manteuffel, G., 2006. Changes of the vocalization during the castration of the domestic pig are indicators of pain. Zuchtungskunde 78, 44-54. Scipioni, R., Martelli, G., Volpelli, L.A., 2009. Assessment of welfare in pigs. Italian Journal of Animal Science 8, 117-137. Velarde, A. and Geers, R. 2006. On farm monitoring of pig welfare. Wageningen Academic Publishers, The Netherlands. Von Borell, E., Schaffer, D., 2008. Welfare conform farm animal housing - a field study based on Critical Control Points from pig farms. Arch. Tierz.-Arch. Anim. Breed. 51, 57-65. Welfare Quality®, 2009. Welfare Quality® assessment protocol for pigs. Welfare Quality® Consortium, Lelystad, TheNetherlands.

16 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Sub-report C: Welfare of weaned, growing and fattening pigs This part updates the underlying report on weaned, growing and fattening pigs: Animal health and welfare in fattening pigs in relation to housing and husbandry (EFSA, 2007b, available at http://www.efsa.europa.eu/en/efsajournal/doc/564.pdf).

Prepared by Xavier Averos1, Sandra Edwards2, Rony Geers3, Giovanna Martelli4, Eleonora Nanoni4, Niamh O'Connell5 and Anna Valros6

176 rue de Saint Brieuc, 35000 Rennes, France. 2Newcastle University, School of Agriculture, Food and Rural Development Agriculture Building Newcastle upon Tyne, NE1 7RU, UK 3Laboratory for Quality Care in Animal Production, K.U.Leuven, Bijzondere weg 12, B-3360 Lovenjoel, Belgium 4Dip. Scienze Mediche Veterinarie, Alma Mater Studiorum - Università di Bologna Via Tolara di Sopra, 50, 40064 Ozzano Emilia (Bologna)- Italy 5School of Biological Sciences, Medical Biology Centre, Queens University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK 6Research Centre for Animal Welfare, Department of Production Animal Medicine P.O.Box 57, 00014 University of Helsinki, Finland

17 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3. Sub-report C: update of the underlying report on adult pigs and unweaned piglets This chapter updates the EFSA scientific opinion on “Animal health and welfare in fattening pigs in relation to housing and husbandry (EFSA, 2007b, available at http://www.efsa.europa.eu/en/efsajournal/doc/564.pdf). The number following the title of the paragraphs by brackets is referred to the corresponding paragraph of the underlying report.

3.1. Current production systems for fattening pigs in the EU (C.6.) Although, in practice, the different housing systems for growing-finishing pigs have not undergone substantial changes since the last published Scientific Opinion (EFSA, 2007b), additional information concerning the effects of these systems exists, basically comparing the effects of often called “alternative” systems with respect to those of more „conventional‟, intensive ones. As the investigated systems, measures used and climatic conditions vary a great deal from study to study, no clear conclusions can be drawn. A national-scale French project, concluded that pigs raised under alternative conditions (that is, pigs provided with litter bedding, the access to an outdoor courtyard, and a total space allowance of 2.4 m2/animal) had a better welfare and growth performance than those raised on fully slatted floor and a space allowance of 0.65 m2/pig, while pork technological quality was poorer (Bonneau et al., 2008). A Brazilian study compared the effect of deep litter systems (solid floor with the presence of bedding materials, and a total floor area of 1.3 m2/pig) with that of more conventional systems (partially slatted floors and 1.3 m2/pig) on the performance, carcass characteristics, meat quality and health condition of pigs (Dalla Costa et al., 2008). But in this case the authors found that, during the growing-finishing period, pigs housed on deep litter showed lower performance and carcass values. Furthermore, a Japanese study determined the effect of outdoor access during the fattening period (Honda and Nakazato, 2009). Indoor pigs were housed on slatted floors, and given 1.8 m2/pig. The space allowance for pigs with outdoor access was 30 m2/pig. When pigs were fed ad libitum, animals with outdoor access were more active and showed a lower performance than pigs housed indoors, although they showed longer loin lengths and thinner back fat. Trombetta et al. (2009) compared different housing systems and different diets. Housing systems consisted of an indoor system (1.5 m2/pig) or an outdoor system (paddocks with the presence of shelters; 30 m2/pig). Irrespective of the diet, pigs reared outdoor showed poorer performance, their carcasses were leaner, and their meat had lower pH 45 min after slaughter and had a lower water content. They concluded that distinct quality features allow a clear differentiation between products originating from outdoor reared pigs and indoor pigs, although differences are not always positive. Cordeiro et al. (2007) evaluated the effect of different production systems on the thermal environment and the performance of pigs. The evaluated systems were deep bedding (wood shavings or rice husk), or traditional concrete slatted floor. In all cases space allowance was 1.66 m2/pig. The thermal confort was similar for the three systems when pigs‟ body weight (BW) ranged between 25 and 75 kg, but the black globe temperature and humidity index (BGTHI) values in the three studied systems were higher than recommended values for pigs ranging between 75 and 120 kg. Nevertheless, concrete floor temperatures were always lower than those in which bedding was used. Overall, performance was similar in the three systems.

18 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Different modifications have been proposed to already existing productive systems. In the case of pigs with an outdoor access, the use of roughage in the outdoor area may promote activity and reduce aggressive behaviours (Presto et al., 2009). In the straw flow system, it has additionally been observed that management routines such as the daily removal of slurry and the application of a solid cover to the slurry storage may be benefitial both for the pigs‟ welfare and for the environment (Amon et al., 2008).

The effects of the production systems may extend to subsequent stages after the end of the growing- finishing period. Barton Gade (2008) compared the effect of different rearing systems, and that of mixing pigs at the moment of loading them onto the truck, on their behaviour during transport and lairage, the blood chemistry at slaughter, and the meat quality characteristics. She found that free range pigs (i.e. those born outdoors and reared in an enriched environment during the growing- finishing period) were more likely to lie down during transport, and displayed fewer aggressive interactions during lairage than conventionally raised pigs. The appearance of skin damage was less frequent among free range pigs, and they also showed higher muscle temperatures early post mortem. In a Swiss survey comparing alternative (pigs given larger, enriched pens, and outdoor access) and conventional systems (Barlocher et al., 2008), the authors found that, in most comparisons, pigs housed under alternative systems exhibited numerically higher pH values both at 35 minutes and at 2 hours post-slaughter. This was attributed to a better adaptation to transport and to the slaughterhouse conditions. Furthermore, Nanni Costa et al. (2007) observed that at loading pigs reared on slatted floors were more difficult to drive along the passageway leading to the vehicle than animals reared on solid floors. The latter pigs were more frequently observed lying in the resting pen. At exsanguination, pigs reared on slatted floors showed significantly higher values of cortisol but similar levels of creatine kinase and lactate with respect to those reared on solid floors.

De Greef et al. (2011) presented the proof of principle of the so-called Comfort Class system for pigs, which was specifically designed to meet the welfare needs of the pigs. Observations showed that tail and skin damage remained at, or were reduced to, a low level (depending on whether pigs already had lesions when entering the system). Resting behaviour was highly synchronised, but synchronisation of eating was limited. The authors concluded that the Comfort Class system probably results in adequate quality of life for pigs (especially based on the absence of observed welfare infringements).

3.2. Factors affecting pig welfare (C.7.) During the last years, studies have increased our understanding of the cognitive abilities of pigs, although the methodology for more systematic evaluation of pig cognition still needs further study (Kornum and Knudsen, 2011; Gieling et al., 2011). For example, Broom et al. (2009) have shown that pigs can use information gained through a mirror to find a food bowl, which indicates assessment awareness in pigs. According to Broom et al. (2009) these results might help us develop more welfare-friendly systems for housing pigs. Van Weeghel et al. (2010) noted that present enrichment materials, even the better ones such as straw and compost, provide extremely limited cognitive challenges to pigs. Along these lines, Driessen et al. (2010) even proposed to revive the idea of designing a computer game for pigs. Puppe et al. (2007) showed that a cognitive enrichment device, combining classical and operant conditioning to food rewards, had positive effects on the

19 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

behaviour of pigs. The authors suggested this might be applicable for animal welfare enhancing management of feeding. More research is needed to increase the understanding of the mental capacities of the pig, and thus allow for more accurate evaluation of housing systems and management solutions that improve pig welfare.

Qualitative approaches to the study of animal behaviour may make an important contribution to the growing interest in animal‟s quality of life (Wemelsfelder, 2007). Douglas et al. (2010) reported that cognitive bias in pigs was changed by enriched versus barren housing, and that this might offer a useful tool to assess affective state of pigs.

3.2.1. Pig genetics in relation to welfare (C.7.1.) In reproductive females, the genetic progress for high prolificacy generates elevated foetal demands for nutrients and space that are not fully met as shown by an increased number of runt piglets having difficulties to adapt successfully to the neonatal life. Hence, artificial nursing and motherless rearing of piglets is becoming more and more practiced, also because the sow does not have enough teats for all born piglets (Prunier et al., 2010). Reduced individual birth weight reduces the likelihood of survival until the end of the nursery period. The importance of piglet birth weight was also confirmed in a study by Fix et al. (2010). They found that a low birth weight of piglets increased the risk of reduced health throughout the fattening period, as well as reduced value at slaughter.

3.2.1.1. Leg problems (C.7.1.1.) Storskrubb et al. (2010) showed that a mild form of osteochondrosis (OCD) is common in both Finnish pig breeds, that bone strength and OCD in the distal end of the femur are moderately heritable and can be improved through selection, and that selection for high meat percentage does not seem to affect bone strength or OCD.

Fan et al. (2009) suggested that in some cases there may be a common genetic mechanism or linked genes regulating fatness and leg weakness. Such relationships are clearly complex, and the utilization of genetic markers associated with both traits should be treated cautiously. Information from a databank containing all pigs slaughtered in Sweden has shown an increased percentage of joint lesions in organic pigs as compared to conventional pigs (Heldmer and Lundeheim, 2010). OCD is one of the main reasons for this increase. As the Swedish organic pigs are of similar genotype to the conventionally reared pigs, this indicates an interaction between environment and genetics on the risks of joint lesions due to OCD (Gångare, 2009).

3.2.1.2. Cardiovascular problems (C.7.1.2.)

No new information.

20 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3.2.1.3. Social behaviour and fearfulness (C.7.1.3.) Lankin (2008) revealed that the sample distributions of the frequencies of defensive behaviour towards humans were significantly dependent on the age and sex of the animals, and on the genotypes of the line. It is suggested that there is a major gene controlling selectively significant behaviour of pigs towards humans.

Rodenburg et al. (2010) indicated that including social effects into breeding programmes is a promising way to reduce negative social interactions in farm animals, and possibly to also increase positive social interactions, by breeding animals with better social skills.

3.2.1.4. Disease resistance (C.7.1.4.) No new information.

3.3. Light inadequacy and noise (C.7.2.) In order to achieve a proper sensory input pigs need a sufficient illumination level in terms of both light duration and light intensity (EFSA, 2007b). Pigs are generally believed to have good visual diurnal capabilities, nevertheless Zonderland et al. (2008a) observed that the pigs‟ ability to resolve visual details shows large individual differences and it is limited when compared to humans. Results from these authors also indicate that the detail of the visual cue (symbol size) has a more pronounced effect on the pigs' ability to distinguish visual cues, compared to the level of illumination: an increase in light level from 12 to 40 lux did not have a significant effect on the pig‟s abilities to distinguish visual cues. With respect to the presence of a specific need of pigs in terms of light duration, Martelli et al. (2009) found that heavy pigs receiving a prolonged photoperiod (14-h vs. 8-h of light/day with a light intensity of 70 lux) had better growth parameters and spent significantly more time resting. Although not significant, a reduction of agonistic interactions was also observed. An even more prolonged artificial photoperiod (16-h vs. 8-h/day light period ) with a lower light intensity (40 lux) compared to the aforementioned study, was also shown to significantly improve the growth and behavioural traits (greater incidence of lying behaviour and lower incidence of pseudo-rooting behaviour) of growing-fattening pigs (Martelli et. al., 2011, in press).

Pigs can distinguish familiar and unfamiliar conspeciﬁcs, and will form stable social groups when given the opportunity, using visual, olfactory and auditory cues. However, this ability may be compromised by environmental factors relating to indoor commercial production systems, where high concentrations of aerial pollutants (e.g. ammonia), low light intensity and high levels of background noise may be present. Aggressive behaviour among newly mixed pigs was exacerbated at low light intensities (~ 40 lux) and at high ammonia concentrations (~ 20 ppm; Parker et al., 2010). In this framework, elevated concentrations of atmospheric ammonia (similar to 20 vs. <5 ppm) and low lighting (similar to 40 v. 200 lux) may undermine the social stability of groups of finisher pigs through a still-unknown mechanism (Parker et al., 2010). Furthermore, there is evidence for brighter light (200 vs 40 lux) to lower the effect of ammonia on salivary cortisol (O‟Connor et al., 2010). These results on light intensity agree with those reported by Martelli et al. (2010) who

21 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

found significantly elevated levels of agonistic interactions between heavy pigs kept at 40 lux instead of 80 lux. On the other hand, pigs exposed to the higher illumination level showed a tendency towards a higher proportion of tactile social interactions. No significant differences were observed with respect to production traits.

In newly weaned piglets, a prolonged photoperiod (20 vs. 8-h of light) during the first four days after weaning resulted in a greater feed intake only on the first day, so that feed intake or body weight gain were not influenced over the entire 7-week nursery phase (Reiners et al., 2010).

At present, it is difficult to fulfill the minimal standards regulated by European rules using natural light only without additional sources of artificical light. The position of the windows is important as wider windows, positioned closer to the floor, could improve light levels in the pen, avoiding the use of artificial light (Costa et al., 2009a). However, pigs housed close to a window were likely to be exposed to a light intensity of 1000 lux or more in summer, resulting in uncomfortable air temperature and increased water requirements (Meyer, 2007).

Common sources of noise in piggeries (fans, feed supplying systems, animals etc..) and the negative effects on pig welfare have recently been reviewed by Scipioni et al. (2009). Sudden noises must clearly be avoided and sources of continuous noise (such as noise from ventilation systems) must also be controlled. As a potential environmental stressor for animals, noise may be responsible for a wide range of changes in production in pigs including muscle degeneration. At 90 dB piglets and growing pigs may show negative physical alterations (increase of heart rate and lower performances). In addition, pigs exposed to a high level of mechanical noise from artificial ventilation (similar to 80 vs. 40 dB) were less submissive in aggressive interactions (Parker et al., 2010).

3.4. Ability to rest and sleep (C.7.3.) Resting behaviour appears to be strongly related to space allowance, with different studies covering this issue during recent years (Anil et al., 2007a; Scott et al., 2007a; Street and Gonyou, 2008; Hötzel et al., 2009; Li and Johnston, 2009). Allometric principles show increasing evidence of their suitability when calculating the spatial needs of pigs according to their behaviour (Petherick, 2007; Petherick and Phillips, 2009). Averós et al. (2010b) used a meta-analytical approach to quantify the effect of different factors on the percentage of time spent in sternal and lateral lying by growing- finishing pigs (19-87 kg). On slatted floors the threshold space allowance, at which the percentage of time spent lying was maximised (about 80% of total time), and from which a gradual reduction in the time spent lying was predicted, was estimated to be 0.039 m2/BW0.667. The threshold space allowance value was much higher for systems with solid floors and no significant effect was found for group size. The presence of enrichment within the pen modifies the behavioural repertoire of pigs, and this can modify the effect of space allowance. Despite this, in another meta-analysis (average space allowance = 0.079 m2/BW0.667 ), Averós et al. (2011) found that the resting behaviour of pigs (defined as the percentage of time lying and sitting) was not affected between 0.025 and 0.070 m2/BW0.667 space allowance. From 0.070 m2/BW0.667 on, they found a

22 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

progressive reduction in the time spent resting with increasing space allowance, independent of the presence or absence of enrichment.

With respect to the spatial requirement of heavy pigs (slaughtering BW of about 160 kg), Rossi et al. (2008) found that a floor space availability of 1.4 m2/pig (k=0.047), calculated on the basis of the space occupied by a laterally recumbent pig, resulted in a tendency towards better growth parameters (improvement of the average daily gain and reduction of the feed conversion ratio) in comparison with a floor space availability of 1 m2/pig (k=0.033).

The presence of different flooring materials may enhance the use of the areas for resting. Nevertheless, few major findings have been reported to date. Savary et al. (2009) tested the use of a synthetic plate on the lying area of the pen, but found little benefit on the resting behaviour of the pigs when housed on straw bedding or on a bare floor.

The presence of a bedding substrate for resting under cold conditions becomes less important for pigs as they grow older. Zhou et al. (2005) found that at ambient temperatures of 9.9 ºC and lower, the proportion pigs up to 48 days old lying on bedding substrate was 98.9%, and this proportion decreased with age.

3.5. Ability to exercise (C.7.4.) The rising interest in alternative husbandry systems which increase the pig's possibility to exercise (outdoor housing and increasing floor space) have some positive implications for pig welfare. However, the relation between pig‟s physical activity and meat quality is unclear. According to Lopez-Bote et al. (2008), forced exercise had no effects in m. psoas major postmortem tenderness and water holding capacity.

One way to increase the activity level of pigs is to facilitate play behaviour. De Jonge et al. (2008c) investigated the effect of music as a context cue for play behaviour and found that music replay facilitated play behaviour in the control group (which had previously heard music but not in combination with access to a playroom), although significantly less so than in the Playroom group (which had previously had access to a playroom when music was played).

3.6. Food and water in relation to pig welfare (C.7.5.) The flexibility of feeding behaviour in the pig makes it difficult to synthesise firm predictions of the relationship between feeding space and performance in different contexts from current knowledge. Other social stressors including group size, mixing of unfamiliar animals and stocking density can adversely affect performance by inhibiting or disrupting access to the feeder, by indirect effects on feed intake through a physiological stress response and by exacerbating the effects of heat stress when pigs are crowded (Manteca and Edwards, 2009).

With respect to feeding behaviour it is worth noting that recent studies did not support the hypothesis (based upon natural foraging strategies of pigs) that pigs would prefer unpredictability when obtaining food in an operant conditioning test (De Jonge et al., 2008a). Furthermore, pigs

23 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

express contrafreeloading when using a natural foraging task and it is suggested that the reinforcing effects of anticipation, which occurs during natural foraging in the delays between searching and finding food, may contribute to the observed expression of contrafreeloading in pigs (De Jonge, 2008b).

3.6.1. Effects of water supply (C.7.5.1.) The recent EFSA opinion on the welfare of fattening pigs (EFSA, 2007b) suggests that the availability of drinking water is important, in particular for dry-fed pigs. As has been studied extensively, water intake influences dry matter intake and therefore pig growth performance. Water can be offered to the pig as part of a liquid diet, or/and as plain, fresh water from a drinker. The EU minimum standards for the protection of pigs state: “All pigs over two weeks of age must have permanent access to a sufficient quantity of fresh water.” Although intuitively logical, this requirement warrants further investigation following the development of new feeding systems as well as the current pressures on environmental aspects of pig husbandry. However, water is an essential part of the nutritive and welfare requirements of pigs, and there are many conditions in which water needs can vary due to the animal's (patho-)physiological state, rearing environment, climatic conditions and diet. For example, animals often stop feeding when they are (becoming) ill. When pigs do not have access to fresh water and can obtain water only through liquid feed, they are unable to use this natural and often functional element of sickness behaviour, which may compromise their welfare further. The evaluation of the water requirements of pigs is complicated because a consumption-based approach may not be accurate due to inevitable waste. It can be questioned if the need for fresh water does indeed exist when all pigs are healthy and when the physiological needs for water uptake have been met by the ration. In such cases it is not certain if additional water intake is associated with a behavioural need, or whether it is redirected exploratory or „playing‟ behaviour or e.g. associated with a need for wallowing (Bracke 2011a, in press). It has been shown that even though the voluntary water intake decreased in pigs given liquid feed, their persistence in obtaining additional water at reduced water flow rates (as a measure of how hard the pigs will work for additional water) did not differ between dry fed pigs and liquid fed pigs in two of three liquid feeding systems (long trough and Variomix). Pigs fed with a sensor system, with 5-10 feeding times per day, were less persistent in their water consumption. The results indicate that depending on the feeding system used, liquid-fed pigs are motivated to work for additional water (Vermeer et al., 2009).

The drinker type can affect water wastage and pig behaviour in the first few days after weaning, during which piglets are known to drink excessively and develop abnormal behaviours. Piglets use more water during the first 2 d after weaning with certain drinker devices. However, the piglets do not appear to attain satiety through water consumption because most of the water used during the first few days after weaning is wasted. From a comparison of three drinker devices i.e. standard nipple, push-lever bowl and float bowl, it was concluded that excessive drinking, water wastage and piglet-directed nosing behaviour can be reduced through the use of push-lever drinker without adverse effects on feed intake and growth (Torrey et al., 2008).

Nannoni et al. (2010) found that in the winter season (i.e. cold season) the absence of an additional supply of fresh water didn't modify growth traits, carcass parameters, animal behaviour or neutrophyl-to-lymphocyte ratio of heavy pigs receiving a liquid low-protein diet when compared to

24 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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animals having free access to an adjunctive source of water (nipple drinker). However, given that there are many physiological, pathological, individual, environmental and managerial (including feed composition) conditions that can increase individual water requirements, the elimination of drinking devices for liquid-fed pigs should be regarded with extreme caution.

3.6.2. Liquid feeding (C.7.5.2.) No new information.

3.6.3. Lack of food and food restriction (C.7.5.3.) Withdrawal of feed can be accidental (automatic feeding system failure/malfunctioning) or voluntary (e.g. pre-slaughter fasting). Feed deprivation of finishing pigs for durations greater than 45 h produced behavioural changes (increased activity) that may be related to increased sensations of hunger. At lower fasting periods (as of 21 hrs) behavioural and physiological adaptations had already taken place (e.g. glucose levels were reduced; NEFAs and B-hydroxybutrate were increased and behavioural activity had decreased compared to controls; cortisol levels, however, were not elevated up to 57 hrs of fasting). This suggests that the pigs were using alternative sources of energy (Toscano et. al, 2007). Fastening duration at farm (from 9 to 18h) had no effect on pig resting behaviour in the lairage pen at the abattoir. However, pigs subjected to 15-h fasting time at the farm showed a higher incidence of lesions generated by fights when compared to pigs subject to a fasting period of 12-h (Costa et al., 2009b).

Production, health (diarrhoea score) and behavioural traits of young pigs fed from either feeders (2 feeding places per pen) or troughs (10 feeding places per pen) were studied by Thomsson et al. (2008). Results indicate that pigs fed from a trough had lower feed conversion rate, and they spent more time in feeding with longer feeding bouts. Trough feeding resulted in lower diarrhoea score for large and small-sized pigs but not for medium pigs. Hoy et al. (2007) compared the effect of a ratio pig:feeding place of 1 : 1 (Piglet-Feeder, Tipp-Feeder) or 5 to 8 : 1 (tube wet feeders) on the performance of weaner pigs. The development of live weight among 1:1 pigs was more homogeneous, as indicated by lower coefficient of variation for average daily gain, compared to 5 to 8:1 pigs. This suggests that higher feeder space availability may be beneficial for weaned pigs.

Jensen and Pedersen (2010) observed that the access to wood chip generally stimulated explorative behaviour and reduced manipulation of floors and pen mates. However, it had no effect on the response to reduced feeding space or delayed feeding. On the other hand, restrictive feeding increased aggression when feeder space was reduced. Feed restriction stimulated foraging-type behaviour in weaned piglets but it did not elicit belly-nosing in all pigs, indicating the existence of a causal relationship between low feed intake and belly-nosing but only for predisposed piglets (Bruni et al., 2008a).

With respect to feeder location, Morrison et al. (2007) observed that the reduction of the distance that the pigs have to walk to feed (which was modified by placing a second feeder in the pen) did not change the duration and the frequency of feed events or growth performance of young animals kept in a deep-litter system in a large group.

25 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3.6.4. Lack or excess of specific nutrients (C.7.5.4.) No new information.

3.6.5. Undesirable compounds in feedstuffs (C.7.5.5.) No new information.

3.6.6. Benefits of specific foods - including feed additives (C.7.5.6.) The benefits of specific nutrients (fibrous fractions, protein), probiotics and essential aminoacids (i.e. tryptophan) on production parameters, health and behavioural traits have been extensively reviewed in the previous report preceding EFSA‟s opinion on growing-fattening pigs (EFSA, 2007b).

Since the European ban on antibiotic growth promoters used in feed, many studies have addressed the effectiveness of a wide array of “alternative” additives to prevent the occurrence of intestinal problems, especially at weaning, and to ameliorate the general health status of the GI tract and the production parameters of pigs. A series of general short overviews on the practical benefits and disadvantages of some of the most commonly used additives in pig production (i.e. acidifiers, enzymes, flavors, mycotoxin binders, prebiotics, probiotics and plant extracts) has been recently reported by Jacela et al. (2009a and 2009b; 2010a, 2010b and 2010c).

The effectiveness of these substances largely depends on the interaction among intrinsic characteristics of the diet (application of suitable technological treatments, digestibility, protein source and level, presence of any antinutritional factors) and farm health and hygiene standards (EFSA 2007b).

The beneficial effects of some probiotics on the intestinal health of piglets at weaning was confirmed by Bon et al. (2010), who found positive effects on feed conversion rate and a dramatic decrease of Escherichia coli levels in the small intestine of piglets receiving a successive supplement of Saccharomyces cerevisiae ssp. Boulardii (6 weeks treatment) and Pediococcus acidilactici (3 weeks treatment). In line with the above mentioned relationship between the efficacy of feed additives and diet composition, Bhandari et al.(2010) found that a lowered dietary protein level (17% CP vs 22% CP) can act synergistically with a probiotic administration, resulting in better performance of piglets after weaning.

Ractopamine, utilized as a feed additive to promote leanness in non-EU countries, may be affecting aggressive behaviour of pigs through indirect action on central regulatory mechanisms such as the dopamine system (Poletto et al., 2010a). Intensified aggression in gilts, especially when fed additive ractopamine, may be linked to reduced central serotonin and greater noradrenergic activity (Poletto et al., 2010b).

With respect to nutrient interactions, Hermes et al. (2009) studied the effects of the levels of crude protein and digestible fibre on the productive performance and health of piglets and found that crude protein showed major effects on the gastrointestinal weight and gut barrier integrity, whereas digestible fibre increased the productive performance and promoted major changes in the microbial

26 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

colonization and fermentation variables. The effect of the dietary protein source on the behaviour of piglets after weaning was investigated by Araujo et al. (2010), who observed that piglets weaned at 21 days fed a corn and soybean meal showed a higher incidence of undesirable behaviours (more nosing and agonistic behaviour, and less feeding) and lower growth parameters when compared to piglets receiving a diet containing spray-dried plasma or nonfat dry milk powder.

Johnson et al. (2008b) showed that the inclusion of hemicelluloses in the diet did not affect the pigs' behavioural repertoire.

Bolhuis et al. (2007b) studied the effects of including pregelatinized vs. native potato starch in the diet of barren-housed and straw-bedded pigs. The starch type did not affect stomach lesion scores which were lowered by straw bedding, reflecting either reduced environmental stress or a positive effect of physical stimulation of the gut. Pregelatinization of starch increased the empty weight of the proximal GI tract, possibly indicating increased nutrient uptake. Further experimental work (Bolhuis et al., 2010a) showed decreased activity and reduced preprandial restlessness, suggesting that fermentable starch enhances interprandial satiety in pigs, and therefore may improve their welfare. Even though effects of resistant starch on activity levels were more obvious in enriched housing, the welfare benefits of fermentable starch may be more pronounced in barren housed pigs as these animals lack an outlet for their increased foraging motivation.

As regards roughage availability, the presence of green lucerne reduced time spent resting in growing-finishing pigs kept either on straw bedding or without straw (Kozera et al., 2009).

Martinez-Trejo et al. (2009) investigated the effects of tryptophan supplemented above requirement levels on social behaviour and productive performance of piglets weaned at 21 days of age. Their results showed that tryptophan supplementation at the higher doses (0.31 and 0.35%) reduced aggression among weaned piglets; however there was no change in productive performance. These results agree with Poletto et al. (2010c) who found that the enhanced tryptophan in the diet reduced behavioural activity and aggressiveness of grower gilts. These results are probably mediated by activation of the brain serotonergic system. These findings indicate that short-term elevation of tryptophan levels in the diet may reduce aggression at mixing in young pigs.

3.7. Ability to explore (C.7.6.) Barren environments provide pigs with few opportunities to express their exploratory, species- specific behaviour, which reduces their welfare. The utilisation of environmental enrichment, by means of the provision of either a bedding material or point-source objects, is therefore a way to enhance the welfare of pigs (EFSA, 2007b). An appropriate enrichment material can be defined as a material which stimulates exploratory behaviour for an extended length of time (Studnitz et al., 2007), preferably comparable to the level of occupation provided by straw. In addition, Van de Weerd and Day (2009) also suggested that successful enrichment should maintain or improve the pigs‟ levels of health, improve the economics of the production system, and be practical to employ. The ability of any enrichment material to fulfill pigs‟ exploratory needs is largely determined by its characteristics. Properties which stimulate exploration best include being complex, changeable, destructible, manipulable and containing sparsely distributed edible parts (Studnitz et al., 2007;

27 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Bracke et al., 2007b). Averós et al. (2010a) also found, from a meta-analysis, that suspended and deformable enrichment materials increased the time pigs spend manipulating them. These are characteristics of many substrates, and research has continued to explore pig preferences according to the enrichment defining characteristics. Using various novel parameters for behavioural intensity, Bracke (2007a) showed that growing pigs 'demanded' hygiene and destructibility more than tinkling sounds associated with enrichment materials. Jensen and Pedersen (2007) used more traditional operant tests to assess the relative attractiveness of maize silage with straw, spruce chips, compost, sisal rope, seed grass hay and chopped straw to pigs. Peat was used as the reference material against which the demand of the other rooting materials was assessed. All tested materials were valued as much as chopped straw, but maize silage with straw, spruce chips and compost were valued significantly higher, indicating that complex, compound rooting materials have a larger capacity than straw to stimulate pigs‟ extended explorative behaviour. Using 3-arm maze tests Jensen et al. (2008) studied pigs‟ preferences for enrichment materials, which were grouped according to their defining characteristics. They found that pigs preferred compost and peat to wood shavings as “Earth” materials but did not express statistically significant differences in their preferences among the other groups of tested materials.

Previous experience appears to be important. The negative effect of a lack of appropriate environmental enrichment during the growing period, reflected in the appearance of tail lesions, was exacerbated when pigs originated from enriched farrowing environments with moderate bedding (Munsterhjelm et al., 2009). However, the lack of enrichment in early life can also have negative long-term effects on pigs: Munsterhjelm et al. (2009, 2010) found a higher incidence of blunted cortisol day-rhythms in fattening pigs (21 wks of age) originating from barren housing; and an increase in agonistic interactions in week 14 in pigs that were housed without substrate-enrichment pre-weaning. These results underline the importance of using enrichment throughout the life cycle of fattening pigs. This is further supported by Chaloupkova et al. (2007a), who showed that the enrichment of the pre-weaning environment with straw and enlarged space substantially reduced the tendency of pigs to behave aggressively during food competition later in life. However, aggression during post-weaning mixing of piglets was not affected by pre-weaning enrichment.

Pigs reared in outdoor pasture systems showed more rooting and foraging behaviour, and less tail manipulation, than those reared in conventional indoor systems (Presto et al., 2008). In indoor systems, Scott et al. (2009c) found that straw bedding reduced levels of investigative behaviour of pen components and penmates. Averós et al. (2010a) also found, in a meta-analysis, that increasing the space allowance/pig only increased the percentage of time spent in exploration if bedding was present. However, given the low availability of straw in some areas of the EU and the incompatibility of its use within an elevated percentage of current pig farms, research has continued into the use of other substrates and the use of small amounts of straw. Jordan et al. (2008) found that providing 100 g of straw or hay per day in a rack to groups of finishing pigs led to increased activity levels during daylight hours (as a result of increased occupation with the enrichment) and to less aggressive behaviour. Jensen et al. (2010a) compared maize silage and straw as rooting materials for finishing pigs in part-slatted pens, and found that pigs manipulated the substrate more, and pen components less when maize silage was provided. They also found that pigs manipulated rooting materials more

28 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

at greater floor space allowances, and that manipulation of penmates was higher before, compared to after, substrate provision. Research with finishing pigs in Brazil showed increased play behaviour and reduced harmful social behaviour among pigs in deep-bedded pens with either wood shavings or rice husks compared with unbedded part-slatted pens (Hotzel et al., 2009). Jensen and Pedersen (2010) found that acces to wood chips stimulated exploratory behaviour and reduced manipulation of the floor and pen mates among growing pigs.

A significant amount of research has looked into the benefits of enrichment with „devices‟ or „toys‟. Scott et al. (2007b) found that pigs, whether kept on fully slatted floors or in a straw-bedded system, spent less than 2% of their time manipulating suspended plastic toys, compared with 21% of time spent manipulating straw bedding. They also found that toy manipulation was not affected by system (straw/slats) or number of toys (either 1 or 4 toys in the fully-slatted system). Subsequent research showed that pigs on fully-slatted floors tended to interact more with a hanging plastic toy than with a toy presented on the floor (Scott et al., 2009c). This supports the suggestion that soiling of enrichment devices may reduce their attractiveness to pigs (see also Bracke, 2007a). Similarly, Nowicki et al. (2008) showed that weaned pigs were more interested in a suspended wooden ball than in a free plastic ball on the floor after the first day post weaning. Elkmann and Hoy (2009) compared the relative interest of pigs in three enrichment devices (pendular beam, cross of chains or lifting beam), and found that pigs were more interested in the cross of chains and least interested in the pendular beam. Out of various toys tested, research in Belgium indicated that a long chain was most suited, especially when placed away from the feeder (Van Tielen et al., 2010). Materials like short metal chains, empty jerry cans and small handfuls of sawdust provide only marginal enrichment for pigs (Bracke and Spoolder, 2008). Bracke (unpublished data) found that pigs interacted more and for longer with a long chain reaching to floor level and supplemented with loose chain ends at nose height compared to various other enrichment devices such as a loose ball on the floor, a large wood block, a hanging chain, a short chain attached to the floor and a chain with a hard plastic ball attached to it. Nowicki et al. (2007) assessed the benefits of an aromatized (vanilla) or standard suspended wooden ball compared with no ball for groups of weaned pigs housed in straw-bedded pens. Fighting during the post mixing period was reduced, and the time spent eating and playing increased, when the aromatized ball was provided. Finally, Smith et al. (2009) found that individually-housed Yucatan minipigs interacted significantly longer with a soft rubber cone (height, 48 cm) than a hard plastic ball (diameter, 21 cm).

Trickett et al. (2009) investigated whether weekly alternation of two contrasting objects (suspended rope and loose wood block) increased enrichment value, and whether simultaneous access increased overall object-directed behaviour in comparison with single presentation of each object. They found that a loose wood block provided continuously in pens with weaned piglets elicited less interaction than the other treatments (i.e. continuous rope, alternation rope-wood, alternation wood-rope and simultaneously present rope and wood). The authors concluded that the rotation of enrichment objects increased novelty but that habituation still occurred, and that rope was very effective in occupying the pigs' time, with interaction levels comparable to those previously reported for straw. Gifford et al. (2007) found that pigs retained the memory of an object that they had been exposed to for two days for at least five days, and suggested that restricting object exposure to less than 2 days may help to maintain the novelty value of rotated enrichment items. It is also worth noting that pigs appear to show a degree of synchrony in their behaviour, suggesting that a sufficient number of

29 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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enrichment devices should be provided to avoid competition (Docking et al., 2008). Averós et al. (2010a) found, in a meta-analysis, that the time spent exploring point-source objects was higher when different point-sources were provided. They also found an interaction between the presence/absence of point source objects and space allowance, so that an increase in the time spent exploring the floor with increasing space allowance was only observed in the presence of point- source objects (rather than bedding enrichment). On many farms the EC Directive (2001) on enrichment materials has been implemented as providing a chain with a piece of plastic (ball or tubing) attached to it. Observations in pregnant sows, weaned piglets and growing/fattening pigs kept in different housing systems repeatedly indicated that the pigs interacted less with the chain when relatively hard balls or tubes were attached to it, compared to the same chain without these materials (Ettema and Bracke, personal observations). To avoid labour and costs, most farmers provide these plastic materials in a rather indestructible way. The materials may be better when they are more destructible (e.g. as indicated by Courboulay, 2006, 2011; Courboulay and Thuard, 2008). However, destructible plastic materials need to be replaced regularly. In addition, destructible plastic materials (and those made of tylene, alkathene, pvc, etc.) pose an environmental and food safety risk as they are ingested or degraded by the pigs and end up in the slurry pit.

A semantic modelling approach has also been used to determine optimum methods of providing environmental enrichment for pigs. Bracke et al. collected available scientific information to construct an enrichment model to calculate welfare scores for enrichment materials and weighting factors for material properties (Bracke et al., 2007a, b; Bracke, 2008). To validate the model, the authors also asked pig welfare experts to assess a wide range of enrichment materials and their characteristics. Materials that generated the lowest scores (on a scale from 0, low, to 10, high) included a mirror (attached to the wall), a concrete block, a rubber mat, a minimal amount of straw, a mineral block, a heavy plastic ball, a chain (with or without a piece of hard wood attached to it), a rubber hose cross, a free toy (sow neck tether), a hanging car tyre, a bucket, an additional operant feeder, a fixed wood block, bite rite and a knotted rope (all median expert scores < 2.5). Materials that generated high scores included forest soil, roughage, fodder beet, maize silage, grass (silage), whole straw with chopped beet roots, with maize silage or with additional feed, a bale of straw, long straw with fir branches and straw with forest bark and branches (all median expert scores >= 7.0). The experts suggested a score of 5.0 as the minimum that they considered acceptable enrichment, and this included material such as compost from a dispenser, straw pellets (loose or from a plastic dispenser) and straw in a metal basket.

3.8. Ability to have proper social interaction (C.7.7.)

3.8.1. Lack of maternal contact (C.7.7.1.) Weaning normally involves the permanent separation from the sow and a major change in diet, occurring simultaneously. Strategies such as the temporary separation before weaning may facilitate the adaptation of piglets to weaning (Berkeveld et al., 2007), while the habituation to solid feed before weaning might help to reduce the post-weaning stress (Weary et al., 2008). Qian et al. (2009)

30 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

reported that piglets weaned at 21 days showed an immediate increase in cortisol and D-lactate levels, DAO activity and a urine lactulose-mannitol ratio that was maintained up to the end of the study (35 days). The piglets also showed an immediate damage in the intestinal tissue that had recovered by day 35. Increasing the weaning age from 4 to 6 weeks, and reducing the crude protein content of the diet (230 vs. 130 g CP/kg) may help to minimize the effects of post-weaning colibacillosis in the absence of in-feed antimicrobial growth promoters (Wellock et al., 2007). Van der Meulen et al. (2010) found that increasing the age of weaning from 4 to 7 weeks in the presence of creep feeding reduced the stress post-weaning and improved the post-weaning feed intake, although no improvement in the functional characteristics of the small intestinal mucosa was observed. The intestinal mucosal barrier is subject to serious damage due to the stress of early weaning (at 21 days of age; Qian et al., 2009). In this study the piglets showed elevated serum cortisol levels throughout the first week post-weaning and even at day 35. Gut permeability was increased prior to morphological changes and permeability lagged behind the restoration of these morphological changes (Qian et al., 2009).

On the other hand, Jarvis et al. (2008) investigated whether weaning at different ages (12 vs. 21 vs. 42 days) affected behaviour, physiology and neuroendocrine function in piglets. Salivary cortisol was reduced after weaning in all groups, but no persisting effects of the weaning age on the HPA axis were found at 90 days. Weight gain was slower for piglets weaned at 12 and 21 days, although no differences between groups were observed at 90 days. Although piglets weaned at day 12 appeared to show more behavioural signs of stress, piglets weaned at 42 days exhibited the onset of belly nosing at 28 days. Therefore, this study raises new questions about the impact of housing together sows and piglets for longer periods of time. Piglets weaned prior to 4 weeks-of-age typically take longer to ingest solid feed, drink excessively and develop oral behaviour problems such as belly nosing and belly sucking (Widowski et al., 2008). Devillers and Farmer (2009) found that piglets weaned on day 21 were more apathetic just after weaning, and had a longer decrease in post weaning eating incidence compared to piglets weaned at day 43. The latter showed a stronger increase in aggression from 2 days before weaning to 1 day after (Devillers and Farmer, 2009).

3.8.2. Contact with other pigs (C.7.7.2.)

3.8.2.1. Mixing of unacquainted pigs (C.7.7.2.1.) Pigs‟ immune system is affected by their social rank at the moment of mixing, with subordinates showing a higher stress response (Hjarvard et al., 2009). Aggression among pigs after mixing has a genetic origin (Turner et al., 2008; D‟Eath et al., 2009a; Turner et al., 2009, 2010; Muráni et al., 2010). The level of aggression depends on the number of groups the pigs in the new group originate from (Marekova et al., 2008). Fels and Hoy (2008, 2010) recommended grouping piglets from few litters, mixing sexes and using small group sizes from both welfare and performance points of view. Aggression after mixing decreases with age, as measured using behavioural and stress-physiological indicators (Coutellier et al., 2007; Devillers and Farmer, 2009). The appearance of aggressive behaviour among newly mixed pigs has been shown to be exacerbated at low light intensities (~ 40 lux) and at high ammonia concentrations (~ 20 ppm; Parker et al., 2010) and by the use of certain feed additives such as ractopamine (Poletto et al., 2010a,b). Li and Johnston (2009) showed that the level of familiarity plays an important role when mixing piglets. Familiar piglets which originated 31 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

from the same farrowing room with group housing during lactation, showed minimal aggressiveness during a 14-d post-weaning period. When piglets from different farrowing rooms were mixed at weaning, they showed significantly more aggressive behaviour and elevated injury scores (Li and Johnstron, 2009).

To reduce aggression at mixing, a short-term dietary supplementation with tryptophan has been proposed (Poletto et al., 2010c), as well as the use of a synthetic maternal pheromone (Guy et al., 2009), butafosfan (Staay et al., 2007) and the use of enrichment objects (Nowicki et al., 2008). Piglet familiarisation or socialisation before weaning, as well as providing them with a manipulable substrate and enlarged space allowance at the farrowing pen, have shown benefitial results in reducing the occurrence of negative social interactions and overall stress levels when being mixed after weaning (Kutzer et al., 2009).

3.8.2.2. Group size (C.7.7.2.2.) Under intensive conditions, recent studies indicate that pigs housed in small groups (18 pigs) grow faster than those in larger groups (108 pigs), and that aggression at the moment of mixing is lower in the case of larger group sizes (Samarakone and Gonyou, 2008). In general, pigs housed in large groups behave less aggressively (Samarakone and Gonyou, 2009). Group size may interact with other factors, such as space allowance, but Street and Gonyou (2008) found no difference in the response to crowding when pigs were kept in large and small groups.

Pigs can adopt different behavioural strategies depending on group size (Estevez et al., 2007). Using meta-analysis, Averós et al. (2010a) found that the total time spent in exploration increased with group size and that the time engaged in negative social behaviours increased with group size in the absence of bedding. In the presence of bedding material, the time that pigs spent in negative social interactions remained practically constant when group sizes increased (up to 200 pigs; Averós et al., 2010a).

3.8.2.3. Space allowance and access to resources (C.7.7.2.3.) In group housed pigs the social relationships are complex, and may result in the occurrence of negative social behaviours. Space allowance may play an important role in the appearance/disappearance of these behaviours (Petherick, 2007). Pigs‟ spatial needs depend, among other things, on body weight and group size, since animals in groups are able to share space in time (Petherick, 2007). The effects of space allowance are often confounded with that of group size, so that it is difficult to disentangle the effects of these two factors. Street and Gonyou (2008), however, found little support for reducing space allowances for pigs in large groups (108 pigs) compared to small groups (18 pigs), indicating that the interaction between space allowance and group size might not be as strong as previously suggested.

Oh et al. (2010) tested the effect of different space allocations on the growth and immune response of weaned piglets. The test was conducted on piglets averaging 6.02 kg, and lasted for 4 weeks.

32 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Space allocations were 0.43 m2/pig (10 pigs/pen), 0.30 m2/pig (14 pigs/pen), 0.27 m2/pig (16 pigs/pen), and 0.21 m2/pig (20 pigs/pen). They found a linear increase in the serum IL-1 and cortisol concentrations with decreasing space allocation, suggesting that the stress associated to decreased space allocations might disrupt piglets‟ cellular immune system.

It is known that the provision of enrichment materials may help to reduce the appearance of aggressive episodes, particularly in the case of point-source objects (van de Weerd and Day, 2009). A recent meta-analysis suggested that space allowance may interact with enrichment (Averós et al, 2010a): Total time spent in exploration increased with space allowance per pig when bedding was present, and time spent exploring other pen items decreased with increasing space allowance per pig if no bedding was provided. Jensen et al. (2010) studied the effects of providing two types of rooting material (maize silage vs. straw) at two space allowances (0.64 m2/pig-17 pigs, and 1 m2/pig-11 pigs). They found no differences in the manipulation of pen mates depending on space allowance, and no interaction with rooting material on this parameter.

3.9. Ability to avoid fear - including noise (C.7.8.) Recent research has produced new observation methods to detect fear in pigs. These methods have been validated during housing, handling and transport of pigs. A detailed analysis of acoustic signals might provide a useful, non-invasive method of assessing the welfare status of pigs. Vocalisation elicited during stressful situations may serve as a differentiated indicator of the quality of a stressor, and may be used for the instantaneous assessment of the internal states of pigs (Duepjan et al., 2008).

Reluctance to move is a common response to different fear-inducing stimuli regardless of the age of animals. However, the combination of being reluctant to move and turning back may be a better criterion to assess fear in domestic pigs during handling (Dalmau et al., 2009).

Individual behavioural tests could be a valuable aid in genetic selection, or in the development of management schemes designed to improve welfare, provided that behaviour is consistent within individuals and reliably associated with relevant welfare measures. It has been found that the human- approach test and open-door test show individual consistency over time, suggesting that they describe behavioural tendencies, and may be useful for predicting the fearful response of individual pigs (Brown et al., 2009).

The exposure of pigs to a novel environment causes a physiological response. Pigs are not inherently stressed by such things as alleys and ramps, but novel experiences cause handling problems and a stress response. To overcome this problem, minimal training can help to reduce the stress associated with these experiences (Lewis et al., 2008). Pigs moved at a moderate pace with only a board, quiet voice and gentle slaps, were essentially unstressed by the procedure. On the other hand, the use of an electric prod resulted in a large proportion of pigs showing both behavioural and physiological signs of stress, some of them being extreme (stumbling and falling). Gonyou (2008) advocated to minimize the use of the electric prod, and to modify the handling techniques and/or the load-out facilities.

33 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3.10. Ability to groom (C.7.9.) Wallowing is closely associated with grooming behaviour (Bracke, 2011a, in press). Wallowing is associated to evaporative heat loss, particularly in the case of high ambient temperature and relative humidity. Huynh et al. (2007) observed, for room temperatures between 16 and 32 ºC, that for each ºC increase in skin temperature the wallowing behaviour (rolling or rubbing the body in a mixture of feces and urine) of group-housed growing gilts increased by 0.19%.

3.11. Thermal inadequacy - including noxious gases (C.7.10.) Optimal temperatures for protecting pigs‟ health, welfare and performance have been defined previously (EFSA, 2007b). Recent studies aiming to define the problem of heat stress suggest that the effect of elevated temperatures on the performance and thermoregulatory responses depends on the magnitude and the duration of heat stress. Moreover, the magnitude of heat stress would affect thermoregulatory responses only at the beginning of the long-term heat acclimation period. Breed effects and inter-individual variability of thermoregulatory responses have to be taken into account when evaluating the thermal environment (Renaudeau et al., 2007; 2008; 2010). Pigs use behavioural adjustment (e.g. increased/decreased contact to pen mates) to bring their ear skin temperature into a preferred zone, mainly during the resting periods (Andersen et al., 2008). Fagundes et al. (2008) found a continuous and linear increase in serum cortisol during a heat stress period, suggesting the use of cortisol as a possible indicator of heat stress in growing-finishing pigs. However, long-term variations in cortisol concentration may be influenced by increasing age and weight more than by the environmental temperature. In assessing animal welfare, it seems more reliable to consider the circadian pattern of cortisol concentration instead of only one value per day (Hillmann et al., 2008). Bioinformatic analysis showed that the mini pigs‟ duodenum and jejunum displayed significant damage during heat stress, most severe after 3 days of treatment (Yu et al., 2010). This type of study might allow the fine tuning of the definition of optimal thermal requirements for pigs and anticipation of negative effects leading to decreased body weight. The final body weight following a period of heat stress decreased about 6 kg compared with pigs that were not heat stressed (Zumbach et al., 2008b).

Pigs at high ambient temperatures, especially in combination with a high relative humidity, should be able to wet their skin for animal welfare reasons (Huynh et al., 2007). Two possible solutions have been investigated, wallowing and fogging.

Mud wallowing followed by water wallowing treatment was found to be the most preferred measure to ameliorate heat stress in weaned piglets compared to other treatments such as water spraying (Anindita et al., 2008; Anindita et al., 2009). Among growing pigs given similar thermal stress amelioration treatments, the best feed conversion ratio values were found for the mud wallowing system (Gnanaraj et al., 2008). Bracke (2010a; 2011a) reviewed the pig‟s motivational basis for wallowing and suggested that wallowing is a complex, natural behaviour of pigs that appears to be 'hardwired' in evolution and that may serve several functions including thermoregulation, skin care, sun-burn protection, health, social and sexual behaviour. This implies that wallowing may not only be important at elevated ambient temperatures, but also in other cases of elevated heat production, such as due to activity (e.g. related to mixing of pigs, transport, sexual behaviour and feeding) and when

34 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

they are suffering from infectious diseases (fever). In a subsequent review (Bracke, in press) the welfare importance of wallowing was assessed systematically using a semantic modelling procedure. The author suggested that wallowing may be more important for pig welfare than has been realised to date. A tentative comparison indicated that wallowing may be considerably more important than non-castration, similar to social contact, but less important than providing food or foraging substrate (and the reduction of related vices like tail biting).

Mud and water wallows are difficult to use on most European pig farms, and therefore other alternatives have been designed. Fogging systems have been proposed in order to improve pig welfare. Courboulay et al. (2008) conduced two trials comparing the behaviour of pigs raised in two similar rooms, one equipped with a fogging system and the second acting as a control room. Results indicated a better comfort in rooms with fogging (Courboulay et al., 2008).

Evaporation characteristics are crucial for an accurate control of fogging and ventilation. Evaporation of water is a generally cost-effective solution to alleviate heat stress. It may, however, also increase indoor humidity (Haeussermann et al., 2007). Operation needs to be adapted to outdoor temperatures and to the availability of water resources (Panagakis and Axaopoulos, 2008). Evaporation characteristics, such as the evaporative fraction and the time for reaching a steady state, were evaluated using a transfer-function model. It was found that the positive effects of reducing the sensible indoor temperature exceeded the negative effects of increased humidity and the temperature-humidity index was decreased (alert situations were reduced from 15.5% to 0.8%). An increase in the weight gain of pigs was also found during hot summer conditions.

Denmark has legislation that has led to the widespread use of sprinking systems, which are recommended to be used for cooling of pigs as of 15 °C (Danish Pig Production, 2007; http://vsp.lf.dk/Publikationer/Kilder/lov_bek/104.aspx).

3.12. Humidity (C.7.11.) No new information.

3.13. Respiratory disorders (C.7.12.) Escobar et al. (2007) investigated the behavioural response to an acute respiratory infection with Mycoplasma hyopneumoniae (Mh) and porcine reproductive and respiratory syndrome virus (PRRSV). Innoculated pigs spent less time feeding, decreased activity and the amount of time spent lying was greater, especially lying in a ventral position and in contact with a penmate. Since sickness behaviour and fever are adaptive responses to infection, these data indicate that pigs with an acute PRRSV infection evoke a behavioural strategy that may support recovery but is indicative of malaise. Pathological signs of Mycoplasma hyopneumoniae are also associated with increased serum haptoglobin at slaughter, which in turn is influenced by components of the farm environment (Amory et al., 2007).

35 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Petersen et al. (2008) reported a prevalence of clinical signs of respiratory disease in 2-17 per cent of Danish finishing pigs. The prevalence of atrophic rhinitis was higher in conventional herds than in specific pathogen-free herds. Ostanello et al. (2007) investigated risk factors connected with pneumonia in heavy weight slaughter pigs in Northern Italy. Pneumonia lesions were found in 59.6% of the lungs (range 3-91%). Farm risk factors related to an increase in the severity of the lung lesions included the presence of breeders within the herd, the starting of a growing cycle during the winter season and the lack of vaccination programmes to Mycoplasma hyopneumoniae. Meyns et al. ( 2011) conducted a study to identify herd-level factors that may influence the prevalence and severity of macroscopically visible pulmonary lesions in Belgian pigs at slaughter. The seroprevalence of Actinobacillus pleuropneumoniae and Mycoplasma hyopneumoniae and the number of pigs/nursery pen were positively associated, whereas average weaning age was negatively associated with the pleuritis score. Risk factors associated with a higher prevalence of pneumonia were the presence of pleuritis and the frequent purchasing of pigs. Sanchez-Vazquez et al. (2009) identified geographical location of the finishing unit as a statistically significant risk factor for enzootic pneumonia-like lesions and pleurisy. Part slatted floors also appeared as a potential risk factor for the presence of these two conditions, versus the use of solid floor with bedding which appeared to be protective.

Maes et al. (2008) reviewed the control of Mycoplasma hyopneumoniae, the primary pathogen of enzootic pneumonia, in pigs. Beneficial management practices and housing conditions include all- in/all-out production, limiting factors that may destabilize herd immunity, maintaining optimal stocking densities, prevention of other respiratory diseases, and optimal housing and climatic conditions. Strategic medication with antimicrobials active against M. hyopneumoniae and, preferably, also against major secondary bacteria may be useful during periods when the pigs are at risk for respiratory disease. Eradication of the infection at herd level based on age-segregation and medication is possible, but there is a permanent risk for re-infections. Nathues et al. (2010) surveyed the occurrence of Mycoplasma hyopneumoniae infections in young pigs. The prevalence in lung tissue of suckling pigs (2.0%) was significantly lower than in nursery pigs (9.3%). Previous use of antimicrobials did not influence the detection of M hyopneumoniae infection. The presence of the porcine reproductive and respiratory syndrome virus (PRRSV), Pasteurella multocida, Haemophilus parasuis, Mycoplasma hyorhinis or Streptococcus suis was correlated with a higher probability of also finding M hyopneumoniae. The history of vaccination, the time of the first or second application, and the type of vaccine (one- versus two-shot) did not influence the detection of M hyopneumoniae.

Beskow et al. (2008) identified risk factors for pleuritis in farrow-to-finish herds in Sweden. The results of the investigation indicate that the prevalence of pleuritis recorded at slaughter can be decreased if gilts are brought into contact with sows at an early age, piglets are free from post weaning diarrhoea, a long empty period between consecutive batches is applied, there is a strict air sectioning between stable units for fatteners and disinfection is performed after cleaning of stables. No associations were found between pleuritis and environmental parameters investigated. However, an increased number of sows in the herds increased the risk of pleuritis. Bacteriological survey showed the important role of Actinobacillus pleuropneumoniae (App). Fraile et al. (2010) also found that the percentage of animals with pleuritis compatible with App infection depended on the existence of an all in-all out by room management system and on App and PRRSV herd seroprevalence.

36 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3.13.1. Air quality (C.7.12.1.) Saving energy by means of lowering the ventilation rate in order to increase inside temperature may have an impact on ammonia concentrations within the piggery. Acute and prolonged effects of 35 and 50 ppm concentrations of atmospheric ammonia (NH3) were associated with an increase in absolute monocyte, lymphocyte and neutrophil counts, as well as in serum cortisol and haptoglobin concentrations, but no effect was found on pig growth performance (von Borell et al., 2007b). O‟Connor et al. (2010) found lower concentrations of salivary cortisol and larger adrenal cortices in pigs reared under 20 ppm ammonia, explained by a downregulation of cortisol production. These pigs also performed less playing behaviour than pigs in non-ammoniated rooms. An interaction between high noise and ammonia was found on pigs‟ health scores, and it was also found that a brighter light ameliorated the effect of ammonia, this fact being reflected in the salivary cortisol levels. However, there was no measurable impact of these potential stressors neither on the productivity of the pigs, nor in any of the other measured physiological parameters. In this study, all other aspects of the pigs' husbandry were optimal; therefore, it is possible that under less favourable conditions, more pronounced effects of ammonia, noise and dim light would be observed on pigs‟ welfare. Atmospheric ammonia at commonly experienced concentrations may undermine social stability of groups of finishers, particularly in the presence of low lighting, though the mechanisms are currently unknown (Parker et al., 2010).

Banhazi et al. (2008) reviewed the likely benefits that might be gained from air quality improvements, and the factors affecting airborne pollutants and environmental parameters. Ammonia, carbon dioxide, viable bacteria, endotoxins, and inhalable and respirable particles were identified as major airborne pollutants which could compromise the health, welfare and production efficiency of animals. They used a general linear model (GLM) to model measured internal concentrations, emissions and environmental parameters in order to predict and potentially control the building environment.

3.14. Gut disorders (C.7.13.) To provide a better understanding and assessment of animal suffering due to infectious disease, information on behaviour and the relationships among easily obtainable clinical/clinical-chemical parameters and behavioural indices, were studied by Reiner et al. (2009). The behavioural pattern changed distinctly during development of model parasitic infection with Sarcocystis miescheriana. Overall activities were reduced from 44% (day 0) to 10% (day 14 p.i.), 34% (day 28 p.i.), and 20% (day 42 p.i.).

3.14.1. Postweaning diarrhoea (C.7.13.1.) Laine et al. (2008) analysed risk factors related to the occurrence of Post-weaning diarrhoea (PWD) on Finnish piglet producing farms. An increased risk of PWD was associated with the regimen of twice a day feeding and feed restriction after weaning, a higher number of sows on the farm and manual rather than automatic temperature control. Wellock et al. (2008) suggested that increasing weaning age and decreasing the level of dietary protein, especially in earlier weaned pigs, may help to maintain enteric health and minimise the effects of post-weaning colibacillosis.

37 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

3.14.2. Diarrhoea during finishing period (C.7.13.2.) Petersen et al. (2008) reported a prevalence of clinical signs of diarrhoea in Danish finishing herds of 0-27 per cent.

Guedes (2008) reviewed the recent information on proliferative enteropathy caused by Lawsonia intracellidaris. Risk factors include transportation, feed change, significant temperature variation, pig flow and flooring.

Correge et al. (2009) identified farming conditions and practices associated with Salmonella prevalence in slaughter pigs. In breeder-finisher herds, farming conditions that appeared related to Salmonella prevalence were primarily the overall health status of the farm, prior veterinary treatments, liquid feeding of pregnant sows and fattening pigs, the condition of drinking pipes in post-weaning, pre-loading and loading conditions and adherence to cleaning and disinfection protocols. In fattening-only farms, the number of breeding units supplying weaners and the number of antibiotics treatments at the fattening stage appeared as risk factors.

3.14.3. Gastric ulcers (C.7.13.3.) The Animal Health Service in the Netherlands reported that the proportion of pigs with stomach lesions had increased in the past 20 years from 36% to 58% in fattening pigs and from 63 to 74% in sows. The proportion of serious stomach ulcers, however, had not increased (GD, 2010).

Scott et al. (2007) compared feeding finishing pigs a dry or liquid diet when housed in either fully- slatted or straw based accommodation. They found that gastric lesions were more pronounced with dry feeding and in the fully-slatted system. In line with this, Amory et al. (2006) reported that finisher pigs housed on slatted floors had a higher gastric ulcer severity score than pigs housed on solid concrete floors, which had a higher score than pigs housed on straw bedding.

3.15. Production related and other diseases - and use of growth promotors (C.7.14.) Grau-Roma et al. (2011) reviewed the most recent knowledge on the epidemiology, diagnosis and control of Post-weaning multisystemic wasting syndrome (PMWS). They highlighted that the important multifactorial 'triggers' of PMWS include the immune and infection status of the sow, the timing of PCV2 infection, variations in the virulence of PCV2, co-infections, immune modulation as well as host genetics and management factors. They concluded that the recent commercial availability of PCV2 vaccines provides an excellent tool for reducing the impact of PMWS and other porcine circovirus-related diseases.

Dorr et al. (2007) demonstrated that PCV2-positive pigs were more likely to have other infections including swine influenza virus (SIV) type A and Mycoplasma hyopneumoniae, porcine reproductive and respiratory syndrome virus (PRRSV). Associations of coinfections and disease effects between PCV2-positive and -negative pigs were greatest in 3-site production systems. Fraile et al.(2009) showed that the risk of PCV-2 and PRRSV coinfection was 1.85 times greater in piglets from a sow with low titers of PCV-2 antibodies than in piglets from sows with medium to high titers, 2.54 times greater in piglets from primiparous sows than multiparous sows and 2.02 greater in farms in an area

38 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

of high pig density than in a low-density area. Andraud et al. (2009) assessed, using a modelling approach, the influence of several management practices within a farrow-to-finish farm on the age of PCV-2 infection. The risk of early infection was significantly reduced when mixing of piglets was reduced at different stages (avoiding cross-fostering and grouping piglets by litters in small pens after weaning). Sow-targeted vaccination delayed the infectious process until the waning of passive immunity and piglet-targeted vaccination considerably decreased the force of infection leading to a dramatic decrease of the total number of infections. Changing from a low (3%) prevalence of PCV- 2-infected semen to a higher one (18%) significantly increased the risk of early infections, whereas reducing replacement rate or changing sow housing from individual crates to group housing had a limited impact on PCV-2 dynamics.

Since the previous EFSA report there has been extensive adoption of a vaccine against porcine circovirus type 2 (PCV2) in order to control the symptoms of PMWS. A number of studies have been published which report the efficacy of this approach. Bischoff et al. (2009) demonstrated in a 1.5 year study involving 2,652 piglets that vaccinated animals had a less severe viraemia with a later onset and no clinical signs of PMWS. The efficacy of vaccination was not influenced by the level of maternal antibodies present at the time of vaccination. On average, vaccinated animals achieved a 2.7 kg higher weight gain and a 1.82% lower mortality rate than placebo-treated animals. Vianello et al. (2010) also showed that PCV2 vaccination significantly improved the average finishing performance, decreased mortality rate by 1.5 % and reduced carcass condemnations by 1.8%. Unpublished data by Parker et al. showed that PVC2 vaccination was associated with reduced levels of tail biting (Anonymous, 2009).

A number of papers on parasitic diseases have been published since the last report. Sefcikova et al. (2007) reported a high prevalence of gastrointestinal parasites in large scale breeding farms in Poland, with faecal samples showing eggs of A. suum (35%), T. suis (60%), and Oesophagostomum spp. (55%).

Sanchez-Vazquez et al. (2010) investigated husbandry practices that influence the prevalence of milk spots (resulting from A suum) in batches of slaughtered pigs. Solid floor with bedding appeared as a risk factor. Those GB herds that had all the stages of production indoors appeared to be at lower risk of milk spots in the liver than herds with an outdoor stage.

Surveys in Spain (Garcia-Bocanegra et al., 2010a,b) highlighted a significant prevalence of Toxoplasma gondii infection in pigs in Catalonia, north-eastern Spain. The individual prevalence in animals over 7 weeks of age was 22.8% and the within-farm prevalence ranged from 7.1% to 36.4%. In a larger survey of the major Spanish pig producing regions, antibodies to T. gondii were detected in 16.6% of fattening pigs and 24.2% of sows. The herd prevalence was 85.0% and the within-farm prevalence ranged from 2.9% to 92.8%. The risk factors significantly associated with T. gondii seroprevalence were the lack of rodent control, presence of cats and the presence of outdoor facilities in the farms. Gomez-Laguna et al. (2011) also highlighted a widely distributed Salmonella infection and Toxoplasma infestation in Iberian pigs farms (73.42% and 54.43% of animals were seropositive, respectively), but a low seroprevalence of Brucella and Trichinella (3.8% and 0%, respectively).

39 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

An area not mentioned in the previous report, but a potential welfare issue, are scrotal or umbilical hernias or kyphosis in finishing pigs. Straw et al. (2009) noted that pigs that died from these problems spent considerable time in the finisher phase, with a probable compromise of their welfare during this time.

3.15.1. Injuries - and pain and leg problems (C.7.15.) Petersen et al. (2008) reported a prevalence of clinical signs of lameness in Danish finishing herds of 1-92 per cent. KilBride et al. (2009) reported the prevalence of abnormal gait in finishing pigs from a representative cross-section of indoor and outdoor herds in the United Kingdom to be 19.7%. The lowest prevalence of abnormal gait in finishing pigs occurred in pigs housed outdoors. However, the difference was not significant because only three farms in the study housed finishing pigs outdoors. In indoor-housed finishing pigs, there was an increased risk of abnormal gait in pigs housed on solid concrete floors with sparse bedding, partly-slatted floors or fully-slatted floors compared with those housed on solid concrete floors with deep bedding in all areas. There was an increased risk of abnormal gait associated with increasing callus, bursitis and capped hock score on the limbs of finishing pigs. A cross section of 93 UK farms showed that bursitis is a common condition of growing pigs and that the associated risk factors for bursitis were a lack of bedding in the lying area, presence of voids and pen conditions which increased the likelihood of injury (Gillman et al., 2008). Rahse and Hoy (2007) also found the quality of the floor (smoothness of surface, floor damages, sharp edges, litter material, degree of soiling, width of the slats) is of large relevance to the claw health of fattening pigs.

Street and Gonyou (2008) found that pigs kept in large-groups (108 pigs/group) had poorer scores for lameness and leg scores compared to pigs kept in groups of 18 animals and that pigs housed in large groups at restricted space allowances (0.52 m2/pig) were more susceptible to lameness (compared to 0.78m2/pig).

Osteochondrosis is a common and clinically important joint disorder, defined as a focal disturbance of endochondral ossification, which has a multifactorial etiology. The most commonly cited factors are heredity, rapid growth, anatomic conformation, trauma and dietary imbalances (Ytrehus et al., 2007). Arthritis (joint inflammation) emerges as an important cause of lameness in pigs that have been moved to the growing and finishing areas. Data on the housing, management and disease factors in the weaning and finishing units from 24 farms with a high incidence of arthritis at slaughter (case herds) and from 25 farms with a low incidence (control herds) showed the following risk factors: too young age at castration, open pen partitions, too young age at weaning, disinfecting pens between finishing groups and a feeding plan in finishers (Heinonen et al., 2007).

3.16. Food Safety related aspects (C.8.) Attempts to reduce the use of antibiotics in (intensive) pig farming leads to a substantial reduction in health and welfare of pigs in the short term. The impact on welfare should be monitored closely.

40 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Conclusions and Recommendations This section on Conclusions and Recommendations was written by the editorial team on the basis of the evidence provided in the previous chapters.

CONCLUSIONS - ADDITIONAL CONCLUSIONS TO THE PREVIOUS EFSA REPORT

1. Evidence for the cognitive abilities of pigs is increasing. Better methods to stimulate cognitive enrichment assessment methods for positive affective state are needed (C.7.). 2. Genetic traits of fearfulness and aggression have been identified and could be incorporated in practical breeding programmes to improve welfare (C.7.8.). 3. There is growing evidence that although pigs are able to discriminate between small visual cues at low levels of intensity, greater light duration and intensity than currently provided on many farms can promote better behaviour by reducing aggression (C.7.2.). 4. Higher feeder space availability is beneficial for newly weaned piglets (C.7.5.3.). 5. Following the ban on use of in-feed antimicrobial growth promoters, there are well researched recommendations for alternative diet formulations to minimise the risk of post weaning diarrhoea (C.7.7.1.). 6. All new data reinforce the importance of providing suitable enrichment materials to allow expression of species relevant behaviours and reduce risk of injurious biting. Destructibility, hygiene and novelty are key elements of suitable enrichment (C.7.6.). 7. Analysis of acoustic signals offers a useful, non-invasive method of welfare assessment (C.7.8.). 8. Provision of cooling facilities for pigs are important in any situation of increased ambient temperature or endogenous heat production (C.7.10.). 9. There is a high prevalence of multi-agent respiratory disease conditions, which can be addressed by better management and vaccination strategies (C.7.12.). 10. Ammonia levels of >20ppm have adverse effects on pig physiology and behaviour (C.7.2. and C.7.12.1.). 11. There is a high prevalence of locomotory disorders on many farms which should be addressed through genetic and environmental improvement (C.7.15.).

41 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

RECOMMENDATIONS AND ASSOCIATED HAZARDS

Recommendation in previous EFSA report Suggested recommendations following the Hazard involved Relevant (EFSA, 2007) present evaluation paragraph

1. Pigs should be provided with such an environment and No change Poor pen design and poor NA management that the negative consequences of poor management welfare such as injurious behaviours, physiological problems and immunosuppression, caused in barren environments are avoided. 2. In order to provide for the need to root with the nose Additional: Absence of manipulable C.7.6 and manipulate destructible materials, each pig should material have access to manipulable destructible material such Pigs should have enrichment early in life to as straw or other fibrous material that does not harm avoid negative long term behavioural the pigs if ingested to such an extent that negative predisposition. effects do not occur. 3. Since indestructible objects such as chains or tyres are Further supported by new information Absence of manipulable C.7.6 not sufficient to provide for the manipulatory need of material pigs, they may be used as a supplement to destructible and rooting materials but not as a substitute for them. 4. Pen surfaces suitable for body-rubbing, and wherever Further supported by new information Absence of grooming C.7.9 possible wallows, should be provided for pigs for opportunities grooming purposes. 5. Where the ambient temperature around the pigs is No change Too high or too low below the lower critical temperature, shelter for ambient temperature outdoor pigs and an insulated lying area should be available to the pigs. At such temperatures inside the

42 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

building, insulating bedding should be provided. Since huddling behaviour disrupts sleep in pigs, the necessity for huddling should be minimised by bedding provision or ambient temperature control. 6. Where the ambient temperature around the pigs is Additional: Too high ambient C.7.10 above 19C in pigs of over 50Kgs and above 25C in temperature weaned pigs, once established on solid feed, measures Since pigs have limited abilities to loose heat should be taken to facilitate heat loss in the pigs. This (they cannot sweat), pigs should be allowed to is best achieved by allowing the pigs to take action to seek cooling when overheated, not only in case cool themselves by visiting a wallow or other place of elevated ambient temperatures, but also in where they can cool themselves such as a cool floor, cases of elevated activity, fever and high shower, or place of greater air flow. Above these metabolism. temperatures, each pig should be able to lie so that it is not in contact with any other pigs. 7. In order to minimise disease in pigs, and hence poor Additional: Inappropriate management NA welfare, effective disease preventive and management procedures should be in place. In addition to health Add the words „and interventions‟, i.e. “more control and health service these procedures include intensive inspections and interventions when e.g. avoiding mixing of animals, daily inspection of all infectious diseases, injury due to aggression, the pigs so that sick or injured animals can be belly-nosing or (tail/ear/flank/leg-)biting is identified and more intensive inspections when occurring” infectious diseases, injury due to aggression, belly- nosing or (tail/ear/flank/leg-) biting is occurring. 8. The lighting in pig houses should not be flashing and Additional: Poor light C.7.2 should be of a wavelength and intensity during the light period that allows pigs to discriminate the Although the ability of pigs to discriminate behaviour of other pigs and materials such as straw between small visual cues at light intensities and to show normal diurnal rhythms. The light level from 12 to 80 lux does not appear to change, and distribution at times of inspection should be a light intensity of >80 lux during activity sufficient to allow each pig to be seen. periods reduces aggression compared to 40

43 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

lux. A minimum light period of 14h/day should be provided where artificial light is used.

9. The design of accommodation for pigs should be such No change Poor pen design NA that the pigs have sufficient exercise for normal bone and muscle development and opportunities to avoid or hide from other pigs that may show aggression, belly- nosing or tail-biting to them. 10. Breeding of pigs in order to eradicate halothane gene Additional: Insufficient or incomplete C.7.8 has significantly improved pig welfare. There should breeding goals be further efforts in selection and breeding methods so Add „fearfulness and harmful injurious that the likelihood of problems of pig welfare, behaviour‟ as classes of behaviour that including cardiovascular malfunction, risk of early selection should try to reduce. death, leg disorders is maintained at a low level. Welfare outcomes concerning the frequency of cardiovascular malfunction, mortality rate and prevalence leg disorders should be defined. Additional: There is a need to better understand the interaction between genotype and environment in the pathogenesis of osteochondrosis and arthritis.

11. Pigs should be exposed to appropriate human contact No change Poor or insufficient human NA early in their lives so that later they are less fearful – animal contact and negative effects on their welfare during the handling of the animals are minimised and there are associated benefits for production.

44 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

12. All pigs should be provided with water of good quality Further supported by new information Poor water quality C.7.5 sufficient for their needs. Water supply systems should be well-maintained and their efficiency regularly checked. N1 There is a need to identify and validate animal NA C.7 based measures of positive affective state

N2 Noise levels in pig housing should be <80dB Too much noise C.7.2

N3 Diets provided to weaned piglets should be Insufficient quality of the C.7.13.1 formulated to reduce the risk of post-weaning diet diarrhoea, using principles which are now well researched.

N4 Appropriate biosecurity and vaccination Poor health management C.7.14 protocols should be implemented to safeguard pig health

N5 Ammonia levels in pig housing should not Poor environmental C.7.2; exceed 20ppm circumstances in the building C.7.12.1

N6 Sick and injured pigs should be hospitalised NA C.7.14 and euthanized without excessive delay

N7 Further research is needed to specify in more Poor pen design C.7.7.2.3 detail the effects of reduced space allowances on negative social behaviours, as well as the interaction between space allowance and enrichment, so as to identify the extent to

45 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

which these factors can act as substitutes for each other. In addition, the interaction between space allowance and group size needs further clarification.

46 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

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47 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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48 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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49 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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50 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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51 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

Haeussermann, A., Hartung, E., Jungbluth, T., Vranken, E., Aerts, J.M., Berckmans, D., 2007. Cooling effects and evaporation characteristics of fogging systems in an experimental piggery. Biosystems Engineering 97, 395-405.

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Jacela, J.Y., DeRouchey, J.M., Tokach, M.D., Goodband, R.D., Nelssen, J.L., Renter, D.G., Dritz, S.S. 2009b. Feed additives for swine: Fact sheets – carcass modifiers, carbohydrate-degrading enzymes and proteases, and anthelmintics. Journal of Swine Health and Production ;17(6):325– 332

Jacela, J.Y., DeRouchey, J.M., Tokach, M.D., Goodband, R.D., Nelssen, J.L., Renter, D.G., Dritz, S.S. 2010a. Feed additives for swine: Fact sheets – fl avors and mold inhibitors, mycotoxin binders, and antioxidants. Journal of Swine Health and Production 8(1):27–32.

52 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Jacela, J.Y., DeRouchey, J.M., Tokach, M.D., Goodband, R.D., Nelssen, J.L., Renter, D.G., Dritz, S.S. 2010b. Feed additives for swine: Fact sheets – high dietary levels of copper and zinc for young pigs, and phytase. Journal of Swine Health and Production 18(2):87–91

Jacela, J.Y., DeRouchey, J.M., Tokach, M.D., Goodband, R.D., Nelssen, J.L., Renter, D.G., Dritz, S.S. 2010c Feed additives for swine: Fact sheets – prebiotics and probiotics, and phytogenics. Journal of Swine Health and Production;18(3):132–136

Jarvis, S., Moinard, C., Robson, S.K., Sumner, B.E.H., Douglas, A.J., Seckl, J.R., Russell, J.A., Lawrence, A.B., 2008. Effects of weaning age on the behavioural and neuroendocrine development of piglets. Applied Animal Behaviour Science 110, 166-181.

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53 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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54 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Nannoni, E., Martelli, G., Mordenti, A.L., Sardi L., 2010. Water requirements of Italian heavy pigs: effect of water restriction in the winter season on production and behavioural traits. Proc.of the LXIV Congress SISVet, Asti (Italy) 7-10 September

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55 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Poletto, R., Meisel, R.L., Richert, B.T., Cheng, H.W., Marchant-Forde, J.N., 2010b. Behavior and peripheral amine concentrations in relation to ractopamine feeding, sex, and social rank of finishing pigs. Journal of Animal Science 88, 1184-1194.

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56 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Savary, P., Gygax, L., Wechsler, B., Hauser, R., 2009. Effect of a synthetic plate in the lying area on lying behaviour, degree of fouling and skin lesions at the leg joints of finishing pigs. Applied Animal Behaviour Science 118, 20-27.

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57 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Turner, S.P., D‟Eath, R.B., Roehe, R., Lawrence, A.B., 2010. Selection against aggressiveness in pigs at re-grouping: practical application and implications for long-term behavioural patters. Animal Welfare 19, 123-132.

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58 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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59 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Sub-report D – Welfare weaners and rearing pigs: effects of different space allowances and floor

This part updates the underlying report on space and floors: The welfare of weaners and rearing pigs: effects of different space allowances and floor (EFSA, 2005, available at http://www.efsa.europa.eu/en/efsajournal/doc/268.pdf).

Prepared by Xavier Averós1, John McGlone2, Hans Spoolder3 and Beat Wechsler4

176 rue de Saint Brieuc, 35000 Rennes, France.

2Dept Animal Science & Food Technology, 123C Animal Sci Building, Lubbock, TX 79409-2141, USA

3Wageningen UR Livestock Research, PO Box 65, 8200 AB, Lelystad, The Netherlands

4Federal Veterinary Office, Centre for proper housing of ruminants and pigs, Tänikon, CH-8356 Ettenhausen – Switzerland

60 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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4. Sub-report D: update of the underlying report on the effects of different space allowances and floor This chapter updates the EFSA scientific opinion on “The welfare of weaners and rearing pigs: effects of different space allowances and floor (EFSA, 2005, available at http://www.efsa.europa.eu/en/efsajournal/doc/268.pdf). The number following the title of the paragraphs by brackets is referred to the corresponding paragraph of the underlying report.

4.1. The needs and functioning of pigs, in particular in relation to effects of flooring and space allowance (D.6.) No new information.

4.1.1. The needs of pigs in relation to the space in which they live (D.6.1.) No new information.

4.1.2. Describing space allowance (D.6.2.) In a study with growing pigs taken to 156 kg body weight (Rossi et al., 2008), the k value concept described in the previous EFSA report (2005) was found to also be appropriate for very heavyweight market pigs.

4.1.2.1. Physical dimensions of the animal (body space) (D.6.2.1.) Pastorelli et al. (2006) used digital photos to estimate, for pigs ranging from 47 to 198 kg, the minimum space allowance and the static requirements by means of linear measurements. They reported that the k value corresponding to the minimum space occupied physically by pigs within this range of BW was 0.028, while the k value calculated by means of linear measurements was 0.041, smaller than the k value of 0.047 originally suggested by Petherick and Baxter (1981). They also concluded that in the weight range from 85-110 kg the current EU directive does not provide sufficient physical space (static space), although between 115-150kg they consider it sufficient.

Averós et al. (2010b) conducted a meta-analysis to determine which factors affect the total lying behaviour (sternally + laterally recumbent) of growing-finishing pigs. They found that the cut-off point for the k value in relation to lying behaviour was about 0.039 for pigs housed on slatted floors, and almost double in the case of non-slatted floors. These values are considerably higher than the cut-off points published by Gonyou et al. (2006) for k values in relation to the optimal performance of grower-finisher pigs, varying between 0.032 and 0.035 for pigs housed either on partially or fully slatted floors. This indicates that lying behaviour is altered before performance is reduced as space availability decreases.

61 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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4.1.2.2. Activity space (D.6.2.2.) No new information.

4.1.2.3. Social space (D.6.2.3.) No new information.

4.1.2.4. Group (and pig size) properties (D.6.2.4.) With respect to static spatial needs, Averós et al. (2010b) found no interaction between space allowance and group size for the lying behaviour of growing-finishing pigs, indicating that spatial needs for resting are independent from group size. Street and Gonyou (2008), studying a variety of behavioural, physiological, health, and production parameters found little evidence in favour of an interaction between space allowance and group size.

4.1.3. Foot size and biomechanical properties (D.6.3.) No new information.

4.2. Current housing systems - in relation to space and floors (D.7.) No new information.

4.3. Types of flooring used in pig production (D.8.) No new information.

4.4. Effects of space allowance (D.9.)

4.4.1. Effects of space allowance on air quality and its consequences (D.9.1.) Pavicic et al. (2006, 2008) showed for both rearing and finishing buildings that the total number of airborne microorganisms correlates significantly with pig housing density.

4.4.2. Effects of space allowance on mobility and injuries (D.9.2.) Averós et al. (2011) reported that pigs become increasingly more active with increasing space allowance.

Furthermore, group size may affect the occurrence of fights among pigs, and therefore of injuries. Samarakone and Gonyou (2008) studied the effect of group size (18 vs. 108 pigs) in grower-finisher pigs housed on fully slatted floors with a k value of 0.034 at the end of the experimental period.

62 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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They observed that the time spent fighting was higher in the small group, but only during the first day of the experimental period.

Street and Gonyou (2008) compared groups of 18 vs 108 pigs, at space allowances of 0.52 vs 0.78 m2 (k>0.034 in the uncrowded treatment throughout the whole experimental period and k=0.025 at BW=98 kg in the crowded treatment) and found an interaction between space allowance and group size for lameness. The crowding treatment resulted in greater lameness scores in large groups and smaller lameness scores in small groups.

4.4.3. Effect of space allowance on disease (D.9.3.)

4.4.3.1. General introduction (D.9.3.1.) Oh et al. (2010) investigated 6 kg pigs held at k values of 0.073, 0.052, 0.047 and 0.038. They found that there was a tendency for ADG to decrease with decreasing k values, and that feed intake did not differ significantly between space allowances. However, smaller k-values had a negative effect on the immune system with a linear increase in IL-1 concentrations.

4.4.3.2. Infectious diseases of significant importance (D.9.3.2.) No new information.

4.4.3.3. Enzootic diseases (D.9.3.3.) No new information.

4.4.3.4. Non-infectious diseases (D.9.3.4.) No new information.

4.4.4. Provision for other needs (D.9.4.)

4.4.4.1. Space utilisation (D.9.4.1.) Averós et al. (2010b) studied the relationship between space allowance and lying behaviour of growing-finishing pigs by means of a meta-analysis of the existing scientific information. They established a significant quadratic relationship between space allowance and the percentage of time spent lying. Moreover, they found a significant interaction between the k-value and the floor type, showing that the relationship between space allowance and lying behaviour is affected by the presence or absence of slats, whereas group size did not show a significant effect on lying behaviour.

63 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Street and Gonyou (2008) compared groups of 18 vs 108 pigs, at space allowances of 0.52 vs 0.78 m2 and reported that space allowance had no effect on lying behaviour, but pigs in small groups spent more time lying ventrally and less time lying laterally than pigs in large groups.

It is known that pigs change their lying behaviour according to the temperature. Hillmann et al. (2005) found that, for temperatures ranging from 21.7 to 27ºC, pigs kept at 0.7 m2 in the lying area tended to lie down more in the dung area than pigs provided with 1.4 m2 in the resting area, and this effect was already observed at lower temperatures. In addition, Hillmann et al. (2008) observed an alteration in the circadian pattern of cortisol on days when pigs were lying in the dung area (high temperatures) or displayed huddling behaviour (low temperatures).

4.4.4.2. Activity space (D.9.4.2.) Pigs usually prefer to rest on solid areas, but Aarnink et al. (2006) found that the percentage of pigs resting on the slatted area of the pen will gradually increase with ambient temperature, up to a maximum value. They found that this maximum, inflection value depended on pigs BW, being 27.5ºC for pigs weighing 45 kg, and gradually decreasing down to 23.4ºC for pigs weighing 105 kg. They also found that from a given temperature value, the frequency of excretions on the resting area gradually increased with temperature, with values being 25.9ºC for 45 kg pigs, and gradually decreasing down to 20.6ºC for 105 kg pigs. The shift in these areas was observed at lower temperatures when relative humidities were elevated, although it may be affirmed that relative humidity has a minor effect on the lying and excretory behaviour of pigs (Huynh et al., 2005a).

4.4.4.3. Interaction space and aggression (D.9.4.3.) Recent studies suggest that increasing space allowance may be a successful means of reducing the prevalence of aggressive behaviours among finishing pigs. Anil et al. (2007a) showed that, for k values ranging between 0.027 and 0.037 at BW = 116 kg, increasing space allowance reduced the number of aggressive interactions and the total injury scores in growing-finishing pigs housed on slatted floors. Similarly, Liorancas et al. (2006) comparing different space allowances in growing- finishing pigs found that the pigs were more inactive and spent more time fighting and biting when housed in pens with a k value of 0.021, at the moment of slaughter, compared to k=0.050. However, other authors did not find an effect of space allowance on aggression-related indicators such as flank bite scores (Street and Gonyou, 2008). Courboulay (2005) compared fattening pigs kept in pens with a space allowance of 0.68m², 0.85m² or 0.97m²/pig (i.e. 10, 8 or 7 pigs/pen) and concluded that increasing space per animal has no major effect on aggressive behaviour, but they did not observe differences in lesion scores except for one of four batches of animals where lesion score was higher at 0.68m²/pig than at 0.97m²/pig. Based on a meta-analysis, Averós et al. (2010a) found no significant effect of space allowance on negative social behaviours (aggressive behaviours, including biting, pushing, as well as redirected explorative behaviours, such as belly nosing, sucking and tail biting).

64 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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4.4.4.4. Effects of space allowance on performance and adrenal responses (D.9.4.4.) Several studies published recently indicate that increased space allowance results in better productivity parameters. Anil et al. (2007a) investigated growth rate in finishing barrows (final BW about 116 kg) housed on fully slatted floors and found that space allowances corresponding to k values of 0.037 and 0.034 (0.88 and 0.81 m2) were significantly better than 0.027 (0.64 m2). Rossi et al. (2008) examined the performance of heavy growing pigs taken to 156 kg body weight with 1.0 or 1.4 m2/pig and kept on solid floors, 20% slatted or totally slatted flooring. They reported that pigs with less space grew slower when over 120 kg and had higher backfat thickness. DeDecker et al. (2005a) increased floor space from 0.54 to 0.78 m2/pig by decreasing group size from 32 to 22 pigs in a wean-to-finish production system and found that the larger space allowance resulted in better ADG. However, the effect of space allowance was confounded with that of group size in that experiment. This is also true for the study of Oh et al. (2010) who compared space allowances of 0.43 m2/pig (k=0.073 at the end of the experimental period; 10 pigs/pen), 0.30 m2/pig (k=0.051; 14 pigs/pen), 0.27 m2/pig (k=0.047; 16 pigs/pen) and 0.21 m2/pig (k=0.037; 20 pigs/pen) to weaned piglets and found that ADG tended to linearly decrease with decreasing space allowance. Street and Gonyou (2008), comparing space allowances in finishing pigs corresponding to k-values of 0.025 and 0.037 at the end of the experimental period, found generally better performance values for the uncrowded treatment. They also compared the effect of small (18 pigs) and large groups (108 pigs) and found that ADG was lower in large groups.

If the negative effect of a reduction in space allowance on growth performance is due to stress, then a parallel response of the HPA axis should be expected. Anil et al. (2007a) did, however, not find differences in the salivary cortisol levels among treatments with different space allowances in finishing barrows. Similarly, Street and Gonyou (2008) did not identify an effect of space allowance on the salivary cortisol levels and adrenal gland analyses in finishing pigs. On the other hand, Oh et al. (2010) found a linear increase in the serum IL-1 and cortisol concentrations with decreasing space allocation in weaned piglets.

Hyun et al. (2005) examined additive stressors including limited floor space, heat stress and regrouping on pig behaviour, physiology and performance. Stressors had additive effects. That is, adding multiple stressors progressively reduced feeding and standing behaviours and increased the neutrophil to lymphocyte ratio.

4.4.4.5. Exploration and manipulation - tail injuries (D.9.4.5.) Averós et al. (2010a) conducted a meta-analysis of information found in the literature to quantify the effect of housing conditions and enrichment on the behaviour of growing pigs. They found that total time spent in exploration increased with space allowance per pig when bedding was present, and time spent exploring other pen items decreased with increasing space allowance per pig if no bedding was provided. In addition, total time spent in exploration increased with group size.

Jensen et al. (2010) studied the effect of providing two types of rooting material (maize silage vs. straw) at two space allowances (0.64 m2/pig with group size being 17 pigs, and 1 m2/pig with group

65 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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size being 11 pigs). They found that a higher percentage of pigs manipulated rooting material in pens with a high space allowance, whereas manipulation of pen mates was not influenced by space allowance.

4.4.5. Effect of space allowance on the carcass and food safety (D.9.5.)

4.4.5.1. Introduction (D.9.5.1.) No new information.

4.4.5.2. Space allowance and carcass composition (D.9.5.2.) Liorancas et al. (2006) reported that offering spacious conditions compared to commercial conditions resulted in higher muscle pH 24 hours post mortem.

4.4.5.3. Space allowance and pig meat safety (D.9.5.3.) No new information.

4.5. Effects of flooring (D.10.) Concrete slats were convenient for the pigs in respect to the risk of slipping, but inconvenient in respect to elasticity and ammonia emission, furthermore they were cold to lie on. Plastic and cast iron slats were too slippery, but better for the environment in respect to ammonia emission, moreover they were warmer for the pigs to lie on (Pedersen and Ravn, 2008).

4.5.1. Effects of flooring on air quality and its consequences (D.10.1.) Banhazi et al. (2008) measured the concentrations of total airborne bacteria, respirable endotoxins, ammonia, and respirable and inhalable particles in 160 piggery buildings in Australia over a 2 year period. The overall mean airborne bacteria, respirable endotoxins, ammonia (NH3), and inhalable and respirable particle concentrations measured were 1.17 x 10(5) cfu m(-3), 33.1 EU m(-3), 3.7 ppm, 1.74 mg m(-3), and 0.26 mg m(-3), respectively. The concentrations of airborne bacteria, respirable particle concentrations and ammonia increased as the level of pen hygiene (cleanliness) decreased, and might therefore be related to the extent of soiled solid flooring.

There have also been a number of studies on the effect of flooring on ammonia emissions from pig buldings. Higher emission rates would be expected to reflect increased concentrations in the aerial environment for the pigs. Rigolot et al. (2010) developed a model to predict gaseous emissions (methane (CH4), nitrous oxide (N2O) and ammonia (NH3)) from pig excreta. This showed that slurry composting on on straw is associated with high ammonia emission (+15% compared to slatted floor). They highlighted the variability related to temperature and farmer practice; for example, in deep-litter housing systems, ammonia emissions from animal housing may vary between 6% and 53%

66 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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of total N excreted, respectively. Arnon et al. (2007) reported that ammonia emission from a straw flow system was lower than literature reference values for forced ventilated fully slatted floor systems. Blanes Vidal et al. (2008), investigating the effect of provision of rooting material on ammonia emissions, demonstrated that a change of the rooting material, from maize silage to straw, caused an increase in the averaged ammonia emission from 1.68 to 2.22 g/h/hpu. Gilhespy et al. (2009) examined the role of additional straw in reducing ammonia emission by reducing airflow across surfaces soiled by urine, and by immobilization of ammonium-N. An increase of 100% straw, broadcast over the entire floor, reduced NH3 emission from pigs by only c. 20%. Hamelin et al. (2010) showed that design of concrete slat could affect ammonia emission when fouled. Compared with the control design that is typically used in pig houses, the presence of a notch resulted in average reductions between 23 and 42%.

4.5.2. Effects of flooring on mobility and injuries (D.10.2.)

4.5.2.1. Flooring and mobility (D.10.2.1.) Thorup et al. (2008) described joint kinetics while pigs were walking on dry, wet and greasy/slippery floors. The pigs' front limbs were more affected by slippery concrete floors than were hind limbs. In an additional study, Thorup et al. (2007) showed by gait analysis that pigs adapted their gait to potentially slippery floors by lowering their walking speed and reducing their peak utilised coefficient of friction on greasy and wet floors compared to dry floors. Moreover, pigs shortened their progression length and prolonged their stance phase duration on greasy floor compared with dry and wet floors. They concluded that greasy floor appeared the most slippery condition to the pigs, followed by the wet and dry floor.

Von Wachenfelt et al. (2009a) investigated the effects of fouled concrete floor conditions on the gait of pigs walking in a curve, compared with clean conditions. Using kinematics and kinetics to record gait parameters and slip frequency they found that pigs can adapt to fouled floor conditions, but heavily fouled floor did not allow safe walking. In a similar study with a fouled rubber mat floor, the soft flooring material improved gait adaptation and improved walking safety (von Wachenfelt et al., 2010). In fouled floor conditions, pig gait adaptation showed a greater reduction in horizontal forces than in vertical forces (Von Wachenfelt et al., 2009b).

4.5.2.2. Flooring and injury in weaners (D.10.2.2.) No new information.

4.5.2.3. Flooring and injury in Grower/Finisher pigs (D.10.2.3.) Courboulay et al. (2009a) compared welfare parameters in finishing pigs kept on 40 straw based farms (S) and 42 control farms (C). They reported that severe lesions (scratches) and lameness were rare, but severe wounds and tail lesions were less frequent in S than in C farms. The post mortem investigations of the claws of the lateral hind legs of 1004 fattening pigs from 17 units showed that the highest frequency of severe claw alterations was found on „Stallit‟ floors, and in pigs from slatted floors with sharp edges or damaged beams. The percentage of leg problems increased with increasing

67 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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degree of soiling. The health situation of claws was relatively good in pigs from units with litter (13 % of pigs). The percentage of perforated floor in the pen and the width of the beams of the slatted floor did not influence the claw health. There was a tendency that pigs with moderate to severe claw lesions were kept on slatted floors with a width of the slats of more than 20 mm.

Scott et al. (2007) compared claw health in finishing pigs housed in either fully-slatted or straw based accommodation and fed a dry or liquid diet. They found that pigs with straw had more severe toe erosions on the foot, while without straw had more severe heel erosions.

KilBride et al., (2009c) investigated a representative cross section of herds in the UK and reported that the lowest prevalence of abnormal gait in finishing pigs occurred in pigs housed outdoors. In indoor-housed finishing pigs, they found an increased risk of abnormal gait in pigs housed on solid concrete floors with sparse bedding, partly-slatted floors or fully-slatted floors, compared to pigs housed on solid concrete floors with deep bedding in all areas.

The quality of the floor (smoothness of surface, floor damages, sharp edges, litter material, degree of soiling, width of the slats) is of large relevance to the claw health of fattening pigs (Rahse and Hoy, 2007).

Savary et al. (2007) tested three types of plastic matting in the lying area of pens for fattening pigs and compared these floors with straw litter and slatted flooring. They found that plastic mats had positive effects on lying behaviour and on the incidence of limb lesions. In a follow up study, however, Savary et al. (2009) investigated the effect of a synthetic plate on skin lesions at the leg joints and concluded that this floor type cannot be considered a better alternative to bare concrete flooring. The synthetic plate did not improve the quality of the lying area in terms of reducing the incidence or severity of skin lesions, and severe types of lesions (adventitious bursae and wounds) were even more prevalent in pens with this type of flooring than in pens with bare concrete in the lying area. Finally, Savary et al. (2011) tested a soft mat (foam covered with a heat-sealed thermoplastic) provided in the lying area of pens for finishing pigs and reported that this mat improved floor quality in terms of preventing skin lesions, compared to bare and slightly littered concrete flooring.

4.5.3. The effect of floor type on disease (D.10.3.)

4.5.3.1. General Introduction (D.10.3.1.) No new information.

4.5.3.2. Infectious diseases of significant importance (D.10.3.2.) No new information.

68 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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4.5.3.3. Enzootic Enteric disorders including internal parasites (D.10.3.3.) Sanchez-Vazquez et al. (2010) carried out an epidemiological analysis on the prevalence of milk spots, resulting from ascariosis, in British slaughter pigs. Solid floor with bedding appeared as a risk factor (OR 1.52) for milk slots in comparison with slatted floors. Using the same sample of animals, Smith et al. (2010) showed that solid flooring with bedding was also a significant risk factors for positive Salmonella meat juice ELISA.

4.5.3.4. Respiratory disorders (D.10.3.4.) Sanchez-Vazquez et al. (2010) carried out an epidemiological analysis on the prevalence of lung lesions and pleurisy in British slaughter pigs. Part-slatted floors were a risk factor for the presence of these two conditions, in comparison with the use of solid floor with bedding which appeared protective.

4.5.3.5. Effects of flooring on other health problems (D.10.3.5.) Scott et al. (2007) assessed the health and welfare implications of feeding finishing pigs a dry or liquid diet when housed in either fully-slatted or straw based accommodation. They found that lameness tended to be more prevalent in the fully-slatted system, whereas in the straw-based system pigs showed more enteric and respiratory disease. Gastric lesions were more pronounced with dry feeding and in the fully-slatted system. In line with this, Amory et al. (2006) reported that finisher pigs housed on slatted floors had a higher gastric ulcer severity score than pigs housed on solid concrete floors, which had a higher score than pigs housed on straw bedding.

4.5.4. Provision for other needs (D.10.4.)

4.5.4.1. Space utilisation (D.10.4.1.) Savary et al. (2009) investigated the effect of a synthetic plate in the lying area on lying behaviour of finishing pigs. They found that floor type in the lying area did not affect the proportion of pigs lying laterally or sternally, or huddling. However, the proportion of pigs lying on the slatted floor next to the lying area was higher in pens with the synthetic plate compared to those with a straw layer in the lying area and was even lower in pens with solid concrete floor in the lying area. These observations may relate to thermoregulation (see below, D.10.4.3).

4.5.4.2. Activity space (D.10.4.2.) Morrison et al. (2007b) compared a conventional fully slatted housing system (1 m2/pig or a k=0.043 at the end of the experimental period, and 15 pigs/group) with a deep-litter system (1.7 m2/pig or a k=0.073 at the end of the experimental period, and 90 pigs/group) and found a trend to higher aggression levels in the conventional housing system at 22 weeks of age.

69 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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4.5.4.3. Effects of temperature (D.10.4.3.) Li et al. (2004) examined pig lying preferences in relation to floor surface temperatures. They found that more than 85% of the pigs used the floor for lying when floor temperature was below 26ºC. With increasing temperature, fewer pigs lay on the floor, and pigs did not lie on the floor when the surface temperature was above 33ºC.

Savary et al. (2009) investigated the effect of a synthetic plate in the lying area on lying behaviour and pen fouling of finishing pigs and concluded that the insulation provided by the synthetic plate may cause problems with heat loss, as the proportion of pigs lying on the slatted floor next to the lying area increased markedly with increasing temperatures. In addition, they found that fouling of the lying area increased as room temperatures rose. This increase did not differ between pens with a synthetic plate and pens with a layer of straw in the lying area, but was less pronounced in pens with bare concrete flooring.

4.5.4.4. Effects of the amount of solid versus slatted flooring on behaviour (D.10.4.4.) No new information.

4.5.4.5. Effects of flooring on maintenance and stress (D.10.4.5.) No new information.

4.5.4.6. Flooring and performance in weaners (D.10.4.6.) No new information.

4.5.4.7. Flooring and performance in finishing pigs (D.10.4.7.) No new information.

4.5.4.8. Floor type and stress physiology in pigs (D.10.4.8.) No new information.

4.5.4.9. Exploration and manipulation (tail injuries) (D.10.4.9.) Courboulay et al. (2009a) found that the occurrence of tail biting was higher and exploratory behaviour was lower in farms without straw bedding compared to farms with straw bedding.

Averós et al. (2010a) conducted a meta-analysis of information on exploratory behaviour of fattening pigs and reported that the lowest predicted total exploration time was found in the absence of bedding and point-source objects, and the highest when bedding or point-source objects were present. In addition, time spent exploring point-source objects was predicted to be higher in the absence of slats and bedding, and lower when bedding or slats were present.

70 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Day et al. (2008) found that the provision of straw of any length to finishing pigs reduced the occurrence of behaviours such as nosing other pigs, aggression and tail-biting compared with when straw was absent. Levels of tail-biting were higher in groups that were provided with chopped straw than in groups with full-length or half chopped straw. They concluded that the use of chopped straw in growing/finishing housing systems, whilst better than no enrichment, is inadvisable.

Scott et al. (2007) observed finishing pigs fed a dry or liquid diet and housed in either fully-slatted or straw based accommodation. They reported that tail-biting tended to be more prevalent in the fully- slatted system and that pigs spent more time manipulating the pen hardware in pens without straw. In line with this, Elkmann and Hoy (2007) reported that fattening pigs provided with enrichment devices used these longer when kept in pens without straw compared to pens littered with straw.

4.5.5. The effect of flooring on the carcass and food safety (D.10.5.) No new information.

Conclusions and Recommendations This section on Conclusions and Recommendations was written by the editorial team on the basis of the evidence provided in the previous chapters.

CONCLUSIONS - ADDITIONAL CONCLUSIONS TO THE PREVIOUS EFSA REPORT 1. The allometric approach appears valid for pigs over a wide weight range (D.6.2.). 2. Behavioural measures suggest a higher optimum k value (0.037-0.039) than production measures (0.032-0.035) (D.6.2.1.) 3. The amount of space needed by an individual appears independent of group size (D.6.2.4.). 4. Walking safety and comfort is impaired by soiled floors (D.10.2.1.). 5. The effects of floor type on health are equivocal, with further evidence that solid floors are better for respiratory disease but detrimental to enteric and endoparasitic infections (D.10.3.)

71 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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RECOMMENDATIONS AND ASSOCIATED HAZARDS

Recommendation in previous EFSA report (EFSA, Suggested recommendations following the New hazards involved Relevant 2005) present evaluation (when applicable) paragraph

1. Improved pen and building design as well as management Supported by further evidence Poor pen design D.10.1 should be considered so that all pigs are provided with a suitable lying area in addition to the dunging area. Both lying in the dunging area and fouling of the lying area should be minimised to avoid increased dirtiness of the pigs and increased odour and ammonia emission. This can be achieved by: (i) increasing the size of the entire pen allowing for a better separation of the lying and the dunging area. These two areas can be of the same floor type but conditions should facilitate differentiation of lying and dunging areas; (ii) providing a dunging area of adequate size so that pigs are not forced to show eliminative behaviour in the lying area, and (iii) by facilitating thermoregulation in the pigs, for example when conditions are extreme, by means of sprinkling or improved airflow patterns. 2. Space allowances and floor quality in housing systems for Supported by further evidence Poor pen design D.10.4.9 both weaners and grower/finisher pigs should facilitate provision of adequate environmental enrichment such as foraging material and material to explore in order to reduce the risk of disturbed behaviour which might include belly- nosing or tail-biting.

72 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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3. All pigs should be provided with thermoneutral conditions No change Too high or too low NA or adequate opportunities to regulate their body ambient temperature temperature, such as heated areas or provision of bedding in cold conditions and increased air velocity, showering or misting systems, or opportunities for lying without body contact in warm conditions. 4. Overcrowding is a risk factor for disease expression and Supported by further evidence Overstocking D.6.2.1; other causes of poor welfare and should be avoided. For pigs of up to 110kg, the minimum space allowance should D.9.4 be equivalent to k = 0.036 where ambient temperature will not exceed 25C. If the ambient temperature is likely to exceed 25C, a space allowance equivalent to k = 0.047 should be used. For pigs of more than 110kg, a space allowance equivalent to k = 0.047 should be used at all times. 5. In order to minimise disease in pigs - especially where No change Poor management NA animal numbers are large - where possible, animals of different ages should be segregated, the design of the buildings should facilitate age-segregated rearing and an all-in all-out policy should be used. 6. In order to minimise the risk of infection, pigs kept No change Disease vectors NA outdoors should be protected from contact with wild mammals and wild boar in particular, for example by the use of appropriate double fences. Outdoor units are difficult to protect. The invasion of birds and rodents should be kept to a minimum. 7. Mixing of unfamiliar pigs should be kept to a minimum, as No change Aggression between pigs NA they are likely to fight and will then have temporarily increased space requirements and an increased risk of diseases, floor-induced claw and limb lesions.

73 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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8. When designing or managing pig systems, efforts should be No change Poor pen or building NA made to minimise aerial pollutants including dust. design ADOPTED BY BIOHAZ. 9. Pig housing systems should be operated and designed to the No change Poor management NA highest standard of Good Farming Practices. ADOPTED BY BIOHAZ 10. The construction, in particular of slatted floors, should No change Poor flooring design NA facilitate the effective cleaning and disinfection necessary for the control and possible eradication of pathogens that cause infectious diseases of significant importance (e.g. foot and mouth disease and classical swine fever) as well as enzootic diseases like Swine dysentery. 11. Efforts should be in place to prevent disease, in particular No change Poor hygiene NA by maintaining good hygiene such as minimising the exposure of the pigs to their faeces and urine. This is of particular importance during the post weaning period. 12. Slatted flooring should be used in the dunging area as it is No change Poor flooring design NA found to result in better pen hygiene and a lower morbidity and mortality in comparison with solid flooring. A successful design for partly-slatted floor systems has been to have the slatted part at a raised level, to allow for straw use. 13. After the EU ban from the year 2006 (EC Regulation No change Poor pen design NA 1831/2003) on the use of antibiotics as a general feed additive to pigs, the implementation of management routines, including space allowances and good pen hygiene as well as other efforts that include selection of floor types that prevent post weaning diarrhoea in particular, is urgently needed as a replacement for the disease preventive effect of antibiotic usage.

74 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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14. Straw and other bedding material should be of good No change Poor straw quality NA hygienic and “physical” quality to avoid negative influence on the health of the pigs including the effects of mycotoxins and other possible contaminants. 15. Small quantities of adequately structured straw or other Supported by further evidence Insufficient manipulable D.10.4.9 materials for manipulation as environmental enrichment for material the pigs to meet their needs can be used on solid or slatted floors. If manipulable material is not provided poor welfare is caused in pigs so it is recommended that this should be provided. 16. When deep litter bedding is used it should be properly No change Poor bedding management NA managed to avoid the build-up of an infectious load of viral, bacterial and parasitological agents - in particular of enteric organisms and pathogens -- in the pig accommodation. It should be added top and be replaced regularly before it becomes a focus for holding faeces. 17. Washing and disinfection of floors should be carried out No change Poor hygiene NA effectively. Fresh and dry faeces and bedding material, such as straw, wood shavings etc. should be removed before cleaning and disinfection. Disinfection without thorough previous cleaning is not useful. The design and the material of the floors and the coving between the walls and floors should allow these operations effectively; therefore surfaces should be smooth and impervious to facilitate free drainage and cleansing of the effluents. 18. In order to maintain good hygiene, slatted (perforated) No change Poor flooring design NA floors in the dunging area should permit faeces and fluids to pass through the gaps. 19. When flooring systems for pigs are designed, building Supported by further evidence Too high or too low D.10.4.3; management should provide optimal conditions for

75 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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thermoregulation. Account should be taken of all of the ambient temperature D.10.4.9 needs of pigs including those for effective thermoregulation and to ensure access to manipulable materials. 20. Metal mesh floors should not be used for pigs because of No change Poor flooring design NA their low slat to gap ratio, and often also the cross- sectional profile of the solid part, causes higher levels of claw injury. 21. Those floors which cause injuries to the pig, e.g. to the Supported by further evidence Poor flooring design D.10.2.3 claw or leg, to a greater extent than those caused by good quality floors should not be used. 22. Where slatted floors are used the gap should not be so No change Poor flooring design NA large that the claw can become trapped or the legs and feet injured. The slat should also be wide enough to adequately support the whole foot of the pig. 23. In slatted (perforated) floors for pigs, according to one No change Poor flooring design NA model the recommendation for the maximum percentage of the floor which is occupied by gaps should be 60% of the usable floor area for an 8 kg weaner, 51% for a 100 kg finisher and 40 % for heavier pigs. 24. Efforts should be made to produce a floor surface which is Supported by further evidence Poor flooring design D.10.2.1 non-slippery and not too abrasive. Gaps or drains should not have sharp edges. 25. When new kinds of flooring are developed, these should by No change Poor flooring design NA fully tested to find out their effects on pig welfare including effects on the claws and legs of pigs, before they are used commercially 26. The design, the size of slats and gaps and the type of floors Supported by further evidence Poor flooring design D.10.2.1 should be adequate for effective drainage or removal of fluids and faeces. Any adverse effects of flooring on the welfare of pigs, including injury and animal health, should 76 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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be prevented. 27. The type of floor used for pigs should allow maintenance Supported by further evidence Poor flooring design D.10.1 of good hygiene and good air quality. Any bedding which is used should be managed so as to avoid the introduction of undesirable pathogens into herds and to minimise ammonia emissions which can cause environmental and health problems. ADOPTED BY BIOHAZ. N1 - A well maintained substrate such as straw Insufficient manipulable D.10.2.3; should be used to reduce leg problems and material D.10.3.5 gastric lesions.

N2 - Provision of mats made of rubber or other Poor flooring design D.10.2.3 synthetic material in the lying area may reduce the incidence of skin lesions, compared to concrete flooring. However, more research is needed to investigate the effects of such mats on the pigs‟ thermoregulatory behaviour and pen fouling.

77 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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78 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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79 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Pavicic, Z., Balenovic, T., Kabalin, AE., Matkovic, K., Popovic, M., Biuk-Rudan, N., Potocnjak, D., Gracner, GG. 2008. Influence of number of piglets per unit of space on microbiological quality of air in rearing unit. Tieraerztliche Umschau 63: 30-35.

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80 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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81 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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82 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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83 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Sub-report E – The risks associated with tail biting in pigs and possible means to reduce the need for tail docking

This part updates the underlying report on tail biting: The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems (EFSA, 2007c, available at http://www.efsa.europa.eu/en/efsajournal/doc/611.pdf).

Prepared by Marc Bracke1, Sandra Edwards2, Rony Geers3, Niamh O'Connell4, Lene Juul Pedersen5 and Anna Valros6

1Wageningen UR Livestock Research, PO box 65, 8200 AB, Lelystad, The Netherlands

2Newcastle University, School of Agriculture, Food and Rural Development Agriculture Building Newcastle upon Tyne, NE1 7RU, UK

3Laboratory for Quality Care in Animal Production, K.U.Leuven, Bijzondere weg 12, B-3360 Lovenjoel, Belgium

4School of Biological Sciences, Medical Biology Centre, Queens University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK

5Aarhus University, Faculty of Agricultural Sciences, Research Centre Foulum, Blichers Allé 20, PO box 50, Denmark

6Research Centre for Animal Welfare, Department of Production Animal Medicine P.O.Box 57, 00014 University of Helsinki, Finland

Preparatory work for pig welfare indicators – Report 2

5. Sub-report E: update of the underlying report on the risks associated with tail biting in pigs and possible means to reduce the need for tail docking This chapter updates the EFSA scientific opinion on “The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems (EFSA, 2007c, available at http://www.efsa.europa.eu/en/efsajournal/doc/611.pdf). The number following the title of the paragraphs by brackets is referred to the corresponding paragraph of the underlying report.

5.1. Current production systems for fattening pigs in the EU (E.2.) Please refer to Sub-Report C.

5.2. Introduction to tail biting issues (E.3.)

5.2.1. Tail biting process (E.3.1.) A new theoretical structure has been suggested to explain the diversity in observed tail biting behaviours. Taylor et al. (2010) distinguished three different descriptive behavioural types of tail biting, namely two-stage, sudden-forceful and obsessive. It is suggested that these behaviours have different motivational bases which respectively may include exploration/foraging, aggression/frustration or nutritional deficiencies/health problems. From this review the authors emphasise that, tail biting is a complicated area and it is difficult to draw conclusions on the precise process from current underlying research. The authors also suggested that tail biting records from abattoirs, while providing large data sets, have restricted usefulness because tail biting is under-recorded and risk factors are mostly unknown. In addition, both farm and abattoir data lack information on the number of pigs which are actually performing the biting.

Ear biting and other forms of biting, such as biting of legs and flanks of conspecifics, may be related to tail biting (which may happen even when the tails are docked). Therefore, it is important to consider these other forms of harmful social biting behaviours as well.

5.3. E.4. Current situation on tail (and ear) biting

5.3.1. Recorded Prevalence in EU (E.4.1.) Smulders et al. (2008) visited 60 farms three times a year across Belgium and found tail lesions in 2.1% and ear lesions in 3.2% of the pigs observed. Overall, at least one animal affected by tail or ear lesions was present in 24.5% of the pens. Goossens et al. (2008) investigated 41farrowing-to-finish farms in Belgium three times during two years and reported that between 0 and 21% pigs showed tail biting behaviour. Tail lesions were found on 3.7% of growing pigs and 2.4% of fattening pigs. The majority of these pigs were docked.

85 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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Boyle et al. (2010b) found that 6.3% of Irish slaughter pigs (36,963 carcasses inspected) had tail damage that could conclusively be attributed to tail biting. A further 51.9% of pigs had minor damage to the tail but some of this could have been caused post-mortem. Furthermore, over 99% of pigs inspected had short tails indicating that tail docking is widespread in Ireland.

Taylor et al. (2010) have emphasised the importance of standardising the criterion for recording a bitten tail, and highlight the concern that projects and surveys may produce results that are not directly comparable unless clear criteria are provided for how lesions and tail- biting indicators were assessed. Mullan et al. (2009) also highlighted the fact that a farm score for dirtiness of pigs has a significant negative correlation with recorded tail lesions. They recommended that, to prevent bias in the recording of tail lesions, farm assurance assessments are conducted on pigs with a prevalence for dirtiness of less than 17%.

Further information on the structure of tail biting outbreaks within a farm has come from a study based on a dataset of 6812 pigs over a two-year period on a pig testing station in Finland. Sinisalo et al. (2010) concluded that the prevalence of tail biting at the pen level is non-linearly related to the porportion of pigs within the pen suffering from tail biting. The authors estimated that in a situation when 50% of pens were affected, 32% of the pigs had bitten tails. By reducing the pen-level biting prevalence to 30 or 40%, only 6 and 12% of pigs suffer from tail biting, respectively. This suggests that the situation on an individual farm may be difficult to ascertain from abattoir prevalences alone, since the pen origin of the pigs is unknown.

At present no general monitoring is performed of levels of tail biting. The pig industry is currently trying to reduce the use of antibiotics to meet consumer safety concerns and, since pig health status is a risk factor for tail biting (EFSA, 2007c, this report), levels of tail biting may be increasing as a result of reduced antibiotics usage. Without general monitoring of health and biting problems (i.e. monitoring of wounds on tails, ears, flanks and legs, tail length and missing parts of the ears), the wider welfare impacts of this industry change cannot be clearly evaluated.

5.4. Welfare and health aspects of tail biting (E.5.)

5.4.1. Behaviour (frustration, biters/bites/victims) (E.5.1.) In a detailed study of tail biting behaviour within groups of weaned pigs, Zonderland (2010) showed that in most pens one or a few pigs could be identified as pronounced biters prior to the tail biting outbreak. Although less clear, often one or a few pigs could similarly be identified as pronounced victims. Prior to a tail biting outbreak, biters not only directed more of their biting behaviour to their pen mates' tail, but also to the enrichment device, suggesting frustrated foraging motivation. Victims were the heavier pigs in the pen and tended to be more often male and more restless preceding an outbreak. Victims also performed more aggressive behaviour, while biters tended to receive more aggressive behaviour.

86 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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5.4.1.1. Injuries, infections and pain (E.5.1.1.) Tail biting, even at the subclinical level, may be painful. Zonderland (2010) showed that pigs with their tails between the legs had a higher chance of tail damage 2-3 days later, possibly reflecting pain or discomfort from initial tail chewing.

Tail biting induces an inflammatory response in the tail leading to an acute phase response and to an increased risk of formation of carcass abscesses in finishing pigs (Heinonen et al. 2010). Munsterhjelm et al (2010) reported that tail biting victims, selected based on observed incidences of tail bites, had more severe tail lesion scores than tail biters and control pigs. In addition, the victims showed a higher level of respiratory infections than the other groups of pigs. It cannot be ascertained, however, which was cause or effect in this association. Kritas and Morrison (2007) found no significant association between the tail score and enzootic pneumonia, but there were significant associations between tail-biting severity and the prevalence of lung abscesses, pleuritic lesions, external carcase abscesses and carcase trimming.

Using a dataset of 6812 pigs on a pig testing station in Finland, Niemi et al. (2010) found that pigs that had been diagnosed with bitten tails grew on average 41 g less per day than healthy- tailed pigs. Serious tail damage decreased growth even further (>120 g).

5.5. Current situation on tail docking (E.6.)

5.5.1. Legislation (E.6.1.) Additional legislation in Denmark requires that no more than 50% of the tail is removed during docking (Ministerial order on tail docking and castration of animals (BEK no. 324, 6 May 2003).

5.5.2. Current practices (E.6.2.) It can be assumed that most pigs in the EU have docked tails, based on surveys in pig houses (Van Tielen et al., 2010). The general EU legislation on the protection of animal welfare does not allow tail docking unless evidence is present that damage to other pig‟s tails has occured despite having taken measures adjusting environmental conditions (including stocking densities) and management practices. However, most farmers do not take any risk, since an outbreak of tail and ear biting may cause considerable (real and perceived) problems in managing the herd until slaughter. Serious biting problems are difficult to stop, or take a long period to stop, and may cause growth retardation, which, when treated inadequately, may impair the flow of animals and result in overstocking.

Perceptions, however, probably play a considerable role in current practices of tail docking. Sixty six percent of 478 conventional Dutch pig farmers reported that they had never tried raising pigs with intact tails and those that had tried showed a very high variation and a non- normal distribution in subsequent levels of tail biting (De Lauwere et al. 2009), indicating a lack of knowledge about actual levels of risk. De Lauwere et al. (2009) also found that the farmers strongly agreed with the statement that it is better to dock all tails then to run the risk 87 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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of tail biting even if it concerns only one bitten pig (average score of 5 on a scale from 1, totally disagree, to 6, totally agree). By contrast, organic farmers had a significantly different opinion (average score of 2.7, n = 32 organic farmers). This indicates that current practices are not only determined by the technical state of the art, but also by prevailing perceptions. Further research may show to what extent prevailing perceptions are valid.

5.6. Welfare and health consequences of tail docking (E.7.) Increased indicators of pain including increased vocalization during the first 60 sec of the docking procedure and behavioural changes, such as increased tail jamming, dog sitting and posterior scooting, have been repeatedly reported in tail docked piglets compared to sham handled controls (Sutherland et al, 2008; Marchant-Forde et al., 2009; Torrey et al., 2009). Processed piglets (tail docking and ear notching combined) had decreased IgG serum concentrations compared with sham-processed and control piglets (Torrey et al., 2009). Total white blood cell counts were also found to be reduced in docked pigs compared with sham controls (Sutherland et al., 2008). Llamas Moya et al. (2007) found that piglets that were ear notched, teeth clipped and tail docked (all treatments together) tended to have higher levels of plasma haptoglobin than untreated controls, but no differences were found in any other immunological parameters (pro-inflammatory cytokines) measured. Age effects were not affected by these husbandry practices, indicating that the combined notching, clipping and docking does not result in systemic inflammation in early postnatal life of piglets.

Rutherford et al. (2009) found that prenatal stress of the dam could increase the acute response of their piglets to tail docking. Piglets exposed to prenatal stress had significantly higher pain scores in response to tail docking compared to controls, and the pain scores for docked litters correlated with mid-gestation maternal cortisol levels. Torrey et al. (2009) compared unmanipulated, sham processed (manually manipulated) and processed (tail docked and ear notched) piglets at either 1 or 3 d of age. They concluded that although tail docking and ear notching do appear to result in short-term pain and modulated immune status, processing on d 1 appears neither better nor worse than processing on d 3.

New information has been published regarding the welfare assessment of different docking methods. Sutherland et al. (2008) compared two methods of tail docking; cautery iron and blunt trauma cutting. Cortisol concentrations were higher in cut compared with cauterised and control piglets. While the behavioural responses to the two methods of tail docking were similar, the elevation in blood cortisol suggested cauterisation to be preferable to blunt cutting. Sutherland et al. (2009b) found that tail biting lesions at 3 and 5 weeks of age were similar in piglets that had been docked with either hot cautery iron, blunt trauma cutting, or had been left undocked. However at 7 weeks lesion scores and C-reactive protein in the blood were increased and body weights were decreased in undocked pigs compared to the pigs that had been docked (with either method). Marchant-Forde et al. (2009) also compared tail docking methods (cold cutting vs. hot iron cutting) as part of a study of different mutilation procedures. Within each litter, 2 piglets, aged 2-3 days, were assigned to 1 of 4 possible procedures: the 2 alternative methods, a sham procedure, and a sham procedure plus blood sampling. For tail docking, hot clipping took longer, and hot-clipped piglets grew slower than cold-clipped piglets. Hot clipping also resulted in longer and higher frequency squealing compared with 88 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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controls. The current data on best method of tail docking are therefore contradictory, and may depend on other aspects such as operator skill.

Herskin et al. (2010) measured neuroma formation in tails docked at variable length, comparing intact tails with tails that were docked for 25, 50 or 75%, resulting in tail lengths at slaughter of 30.6±0.6, 24.9±0.4, 19.8±0.6 and 8.7±0.6 cm respectively. They found that formation of neuroma tissue was increased in shorter remaining tails. This relationship may directly relate to an increased number of nerve fibres cut when docking tails shorter, and suggests that levels of pain associated with tail docking may increase when a larger part of the tail is removed.

Kluivers (2010) has highlighted that no anesthetics are registered for use in piglets to provide pain relief during procedures such as tail docking.

5.7. Hazard identification for tail biting (E.8.)

5.7.1. Animal characteristics (E.8.1.)

5.7.1.1. Breed and genetics (E.8.1.1.) In a case study on a pig farm in Belgium a higher risk for tail and ear biting could be associated to a specific boar line (Van Thielen et al., 2010).

In recent years a new breeding strategy, called group selection, has been proposed as a possible solution for reducing existing problems with tail biting, feather pecking and other harmful social behaviours observed in farm animals (Bijma et al., 2007a, b; Rodenburg et al., 2010). In the prevailing breeding strategy, which is based on individual selection, individual animals may obtain high breeding values when they are producing well at the expense of pen mates, i.e. when they perform harmful social behaviours such as tail biting. In group selection, the performance of group/pen mates is included in the calculation of an individual animal‟s breeding value, and this is expected to lead to more „sociable swine‟ and maximising total genetic improvement (Bijma et al., 2007a, b). A complicating factor for implementation of group selection in practice is that whereas victims of tail biting are easily identified (they have wounds), it is much more difficult to determine which were the biters, i.e. which were the individuals that started the outbreaks of tail biting. As a consequence, whereas young gilts are often disqualified for breeding when they have (severe) tail wounds, perpetrators can be sold as breeding gilts. This implies that at present the selection presssure against tail biting problems is suboptimal. The extent to which group selection can actually solve tail biting problems, however, is not known at present.

5.7.1.2. Gender (E.8.1.2.) In accordance with other abattoir studies, Kritas and Morrison (2007) reported that castrated males showed more tail-biting lesions than females.

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Sinisalo et al. (2010) reported that the percentage of tail-biting victims in a dataset of 6812 growing-finishing pigs from one farm, was lowest (6.8%) in barrow-only pens, followed by female-only pens (13.5%) and boar-only pens (14.0%) of fattening pigs. When both single- and mixed-sex pens were included, intact boars were bitten most (14.6%) and females (11.3%) were bitten more than barrows (8.3%). Boars were indicated as biters (0.8%) more often than females (0.5%) or barrows (0.2%). In contrast, Zonderland et al. (2010) found that in mixed- sex pens male weaned pigs developed tail damage most rapidly and had a higher tail damage duration than females. In single-sex pens the quickest tail damage development was found in all-female groups and these had a greater tail damage duration than all-male and mixed-sex groups. These results indicate that female pigs are more likely to become biters and male pigs are more likely to become victims. However, at the end of the observation period (32 days after weaning), tail damage had developed to high levels in all groups and, at that point, differences between all-female groups and the other groups were absent.

Rydhmer et al. (2010) compared the behaviour of entire males (E) with immunocastrated pigs (Improvac®; I) and surgically castrated pigs (S). They reported that E showed more manipulation of tails compared to I after the second injection of I pigs (4 weeks before slaughter); E also showed more tail manipulation compared to S after the second injection; and E showed more manipulation of ears compared to I and S after reduction from 8 to 4 pigs per pen (2 weeks prior to slaughter of the lightest pigs).

5.7.1.3. Weight or age (E.8.1.3.) Zonderland et al (2010) found that, in weaned pigs, victims were the heavier pigs in the pen.

5.7.2. Rearing (E.8.2.)

5.7.2.1. Early housing conditions (E.8.2.1.9) In an observational epidemiological study on 60 farms visited three times a year in Belgium, Smulders et al. (2008) found that tail and ear biting lesions during the fattening period were affected by several factors in the early housing conditions, including the temperature and the number of feeding places per animal in the nursery, the percentage of floor space covered with slats in the farrowing unit and the feed type in the growing unit.

In an experiment looking at different sequences of moderate enrichment (wood shavings and chopped straw) in suckling, nursery and fattening accommodation, Munsterhjelm et al. (2009) found that an increase in tail lesions was seen when groups of pigs from an enriched farrowing environment were kept in a barren environment during the fattening stage, indicating frustration caused by a reduction of environmental enrichment status. However, a lack of enrichment in the farrowing unit increased agonistic behaviour (including tail and ear biting in the fattening unit at 14 wks of age). They concluded that moderate bedding of farrowing pens seems to reduce agonistic behaviour later in life, although removal of it may increase redirected behaviour, including tail biting. In addition, Munsterhjelm et al. (2010b) reported that moderate enrichment during the farrowing and nursery stages positively affected the

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development of cortisol rythmicity in fattening pigs, and that agonistic behaviour and tail lesions were more common in groups lacking in normal cortisol rhythm.

5.7.2.2. Weaning age (E.8.2.2.) No new information.

5.7.3. Social environment (E.8.3.)

5.7.3.1. Group size, space allowance and stocking density (E.8.3.1.) Goossens et al. (2008) showed that space allowance of less than 0.31m2 for growing pigs (30- 40 kg) increased the proportion of pigs with tail lesions from 0.07% to 0.17%.

5.7.3.2. Other aspects of the social environment (E.8.3.2.) No new information.

5.7.4. Herd size (E.8.4.) No new information.

5.7.5. Flooring and substrates (E.8.5.)

5.7.5.1. Floor type (E.8.5.1.) Courboulay et al. (2009) carried out welfare assessment protocols on farms differing by their type of floor: either concrete, fully or partially slatted (C; n = 42) or straw bedding (S; n = 40). Observations were carried out on 40 to 60 pigs per room for three periods (90, 130 and 162 days of age). Severe wounds and tail lesions were less frequent on straw (S) than on concrete (C).

5.7.5.2. Enrichment (E.8.5.2.) Presto et al. (2008) observed that tail manipulation occurred less often in pigs kept on pasture than those born outdoors but subsequently housed indoors.

Mullan et al. (2011) devised a set of pig keeping system descriptor scores whereby a finishing pig farm was classified on a scale of 1 (legislation compliance) to 5 (highest level of welfare provision) for six different elements of pig husbandry which can influence pig welfare (environmental enrichment, foraging behaviour, thermal comfort, physical comfort, tail docking and floor space provision). Scores achieved when assessing the environmental enrichment and physical comfort elements were significantly positively correlated with a qualitative assessment of good mood of the pigs and a measure of appropriate oral manipulation, and significantly negatively correlated with the prevalence of tail lesions.

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However, there were wide variations in the prevalence of animal-based welfare outcome measures between farms with the same system descriptor score.

5.7.5.3. Straw (E.8.5.2.1.) Courboulay et al. (2009a) compared welfare parameters in finishing pigs kept on 40 straw based farms (S) and 42 control farms (C). They reported that severe wounds and tail lesions were less frequent in S than in C farms.

Zonderland et al. (2008b) compared four preventive measures for tail biting (chain, rubber hose cross, straw rack (5 g/pig/day) and the provision of straw on the floor twice daily by hand (2 x 10 g/pig/day) in weaned piglets. The incidence of pens with wounded pig tails was significantly lower when straw was provided twice daily (8% of pens) compared to the chain (58% of pens) and rubber hose (54% of pens) treatment, but did not differ significantly from the straw rack treatment (29% of pens). Tails with bite marks were significantly less common in pens with twice daily straw (16% of pens) compared to chain (88% of pens), rubber hose (79% of pens) and straw rack (75% of pens). The authors concluded that tail biting is best prevented with a small amount of straw, provided twice daily on the floor, and to a lesser extent with a straw rack, compared to providing a chain or a rubber hose cross.

Zonderland (2010) also reported that the provision twice daily of a handful of long straw strongly prevented tail biting from arising; in pens without straw almost all pigs performed and received tail biting behaviour at low levels prior to a tail biting outbreak. Straw provision can also be effective in controlling an ongoing outbreak of tail biting (Zonderland et al., 2008b). Munsterhjelm et al. (2009) found that presence of some limited straw enrichment increased tail lesion indices in the nursery and decreased them in the fattening unit; giving fattening pigs moderate amounts of enrichment, in the form of wood-shavings mixed with 1/3 chopped straw twice a day decreased the occurrence of tail lesions.

Comparing different lengths of straw for pigs (no straw bedding, full-length straw, half chopped straw, and fully chopped straw) Day et al. (2008) found that the length of straw affected both the quantity and quality of straw-directed behaviours. The provision of straw of any length reduced the occurrence of behaviours such as nosing other pigs, aggression and tail- biting compared with when straw was absent. Pigs were not able to manipulate the chopped straw in the same way as full-length or half chopped straw, and levels of tail-biting behaviour were higher in groups with chopped straw compared to full-length or half chopped straw. Day et al. (2008) concluded that chopped straw in growing/finishing housing systems, whilst better than no enrichment, is inadvisable because of the possibility that levels of adverse pen-mate directed behaviours will increase.

5.7.5.4. Rooting material – earth, peat, compost (E.8.5.2.2.) No new information.

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5.7.5.5. Hanging toys, footballs, etc. (E.8.5.2.3.) Courboulay (2006) compared groups of ten pigs raised on concrete slatted flooring with either a prototype object (T: six plastic hose pipes reinforced by six metal chains fixed on the floor) or long straw provided via a rack. Pigs spent more time in investigating straw than the object, but neither negative social behaviours nor the amount or severity of lesions differed among treatments suggesting that pigs may have reached a sufficient level of exploration of the environment. Courboulay and Thuard (2008) compared animals having either the same toy (T : six plastic pipes fixed on the floor) or a chain hanging at snout level (C) during the post weaning period and then one of these objects during the fattening period. Object investigation during the fattening period was higher in the CT sequence than in TT, suggesting a rebound effect of previous inadequacy. A high level of tail lesions was scored in all sequences except TT, and this sequence was considered as the better recommendation of the combinations tested.

Comparing three chain-based objects (a chain hanging at snout level (C1), at 5 cm above the floor (C2) or a combination of three chains fixed to the floor (C3)), Courboulay (2011) indicated that chains induced manipulating activities by fattening pigs and the extent of the manipulation depended on their accessibility (respectively, 6%, 9% and 13% of observations). The use of the ground fixed chains was similar to that of the same device comprising additional plastic hoses. No tail lesions occurred in the first experimental batch, however more tail lesions were observed with the longer chain C2 than with the chain hanging at snout level (C1) in the second batch.

5.7.6. Diet and feeding (E.8.6.)

5.7.6.1. Restricted level of feeding and high feeding competition (E.8.6.1.) Smulders et al. (2008) found that the risk for tail and ear biting lesions during fattening was negatively correlated to the amount of feeding places per animal in the nursery.

5.7.6.2. Form of feed (E.8.6.2.) Smulders et al. (2008) found that the risk for tail and ear biting lesions during fattening was increased by dry feeding as compared to wet feeding in the growing unit.

5.7.6.3. Minerals (E.8.6.3.) No new information.

5.7.6.4. Protein and amino acids (E.8.6.4.) Martinez-Trejo et al. (2009) compared four levels of dietary tryptophan (0.23%, Control; 0.27%; 0.31% and 0.35%) in piglets weaned at 21 days of age. Frequency of biting ears and tails was reduced from 53.6 to 25.3, 15.1 and 12.2 respectively.

93 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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5.7.6.5. Fibre (E.8.6.5.) No new information.

5.7.6.6. Specific raw materials (E.8.6.6.) No new information.

5.7.6.7. Feed additives (E.8.6.7.) No new information.

5.7.6.8. Sudden changes in feed (E.8.6.8.) No new information.

5.7.6.9. Water provision (E.8.6.9.) No new information.

5.7.7. Health/disease (as ‘causal’ factor) (E.8.7.) An epidemiological study by Smulders et al. (2008) showed that introducing a foot bath between different sections of the farm was associated with a decreased risk for tail and ear biting lesions in farrow-to-finish pig herds. This might be related to a generally positive attitude towards hygiene and preventive health care on the farm.

5.7.7.1. Growth retardation (E.8.7.1.) No new information.

5.7.7.2. Disease (E.8.7.2.) Munsterhjelm et al (2010) reported a high general incidence of pathological findings in pigs from a farm with tail biting problems. This was true of all categories of pig, and not just those which were tail bitten, suggesting that health status might be a predisposing factor on this farm.

Unpublished data by Parker et al. showed that PVC2 vaccination reduces the risk of tail biting (Anonymous, 2009).

5.7.7.3. Parasitism (E.8.7.3.) No new information.

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5.7.8. Climate and ventilation (E.8.8.)

5.7.8.1. Time of year (E.8.8.1.) No new information

5.7.8.2. Heat stress (E.8.8.2.) Courboulay et al. (2008b) compared the behaviour of animals raised in two similar rooms, one equipped with a fogging system and the second considered as a control room. In the first trial, a heating system was used in order to simulate summer temperatures. In the second trial, ambient temperature depended only on weather conditions. Pigs in the room with the fogging system had more scratches in both trials but tail wounds were more frequent in the control room.

5.7.8.3. Cold and draughts (E.8.8.3.) No new information

5.7.8.4. Air quality (E.8.8.4.) No new information

5.7.8.5. Ventilation type (E.8.8.5.) No new information

5.7.8.6. Light (E.8.8.6.) No new information

5.7.9. Tail docking as a control measure (E.8.9.) A Danish investigation (Thodberg et al., 2010) compared the risk of tail biting in pigs tail docked leaving 2.9 cm, 5.7 cm or 7.5 cm or intact tail in 4 herds and a total of 91 pens. The risk of tail biting was only significantly reduced when tails were docked leaving only 2.9 cm of the tail, although trends for a progressive effect were seen. Log odds-ratio for pigs docked leaving 5.7 cm., 7.5 cm. and intact tails were 2.8, 3.3 and 4.6 compared to pigs docked to a tail length of 2.9 cm. Sutherland et al. (2009b) also compared long and short docking (leaving 5 and 2 cm of the tail respectively) and found that tail lesions during the subsequent fattening period were higher in long docked pigs compared with short docked pigs, and that welfare of these tail-bitten pigs was compromised as indicated by severity of lesion, level of C-reactive protein and reduced pig bodyweights.

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5.7.10. Presence of pig(s) with tail injury (E.8.10.) Niemi et al. (2010) have shown that the probability of further tail biting incidences in a pen after the first case has been reported is approximately 0.55. After the first case, the next biting is usually seen within 1-2 days. Statham et al (2009) reported that in five studied pen outbreaks a small runty pig was tail bitten in the absence of a full outbreak. Whenever this happened, a full tail-biting outbreak always went on to take place sometime afterwards.

5.8. Risk assessment approach (E.9.) No major new hazards, or modifications of existing ones, were identified in relation to tail biting, either in docked or undocked pigs.

It is proposed, however, that biting wounds as found on tails, ears, flanks and legs are major animal-based indicators of pig welfare. In addition to measuring wounds, monitoring healed wounds, i.e. measuring the degree to which pigs have intact ears and tails (e.g. tail length), also needs to be considered. Tail length, in particular, should be as long and intact as possible, and may allow detection of previous tail biting problems, especially when tails cannot be docked any shorter than a specified minimum length. The presence of an undocked and undamaged tail may be an appropriate “iceberg indicator” of good pig welfare, indicating that nutrition, environment and general husbandry are in accord with the needs of the pig.

5.9. Management of tail biting outbreaks (E.10.) Niemi et al. (2010) have shown that tail biting spreads with epidemic-like features within the farm. The probability of further tail biting incidences in a pen after the first case has been reported is approximately 0.55. After the first case, the next biting is usually seen within 1-2 days. In addition, as more pens are affected the prevalence of tail biting, the total incidence of tail biting increases exponentially. It is therefore very important to stop the tail biting at an early stage.

Zonderland et al. (2009) found that tail damage affects both tail posture and tail motion at the same observation moment. Furthermore, tail posture could predict tail damage, but tail motion had no predictive value for tail damage. When a piglet was observed with a curled tail (and no tail damage), the chance of bite marks or a tail wound 2-3 days later were 8.6% and 3.5% respectively. When a piglet was observed with its tail between the legs (and no tail damage), the chance of bite marks or a tail wound 2-3 days later increased to 22.3% and 8.5%. Furthermore, when a piglet was observed with its tail between the legs (and no tail damage) in two consecutive observations, the chance of bite marks or a tail wound 2-3 days later increased further to 32.4% and 23.7%. It was concluded that a piglet's tail posture is strongly related to tail damage at the same moment and can predict tail damage 2-3 days later. Checking tail postures on a regular basis increases early recognition of tail biting, provided the piglets‟ tails are not docked completely. This can help pig producers to take appropriate measures to prevent further escalation of the problem.

Statham et al. (2009) also examined whether it would be possible to predict an outbreak of tail-biting in groups of undocked pigs followed from birth till slaughter, by retrospectively 96 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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comparing 6 no-outbreak groups with 9 groups that had an underlying outbreak and 6 groups with a severe outbreak of tail-biting. All outbreaks occurred after 11 weeks of age. Four days prior to an outbreak activity levels were significantly higher in severe outbreak groups, with more pigs standing and fewer pigs sitting or lying inactive than in matched controls. At 7 and 11 weeks of age, prior to any outbreaks, no differences were found in activity levels between groups, but tail interest was higher and both damaging tail-biting and tails tucked under were lower in no outbreak groups than in those with severe outbreaks. Thus, while damaging tail- biting may be a good predictor of impending outbreaks, high levels of tail interest are not. Whenever a small runty pig was tail bitten in the absence of a full outbreak, a full tail-biting outbreak always went on to take place sometime afterwards. The occurrence of single tail- biting events may thus be reliable indicators of future outbreaks. They concluded that, measurement of pig activity has potential for predicting tail biting outbreaks on commercial farms as do levels of tails tucked under and damaging tail contact. The presence of an 'indicator pig' might also be a useful sign that an outbreak will occur. However, tail biting outbreaks are variable and difficult to predict from single measures.

Zonderland et al. (2008b) compared two curative treatments (removal of the biter and straw twice daily) in weaned piglets. No significant difference was found between the curative treatments, both of which showed a reduced incidence of red fresh blood on the tails at days 1- 9 following curative treatment, compared to day 0. However, neither curative treatment eliminated tail biting entirely. This study indicates that, once tail biting has occurred, providing a small amount of straw twice daily and removing the biter appear to be equally effective.

Taylor et al. designed a web based pig husbandry advisory tool (WebHAT) to solve biting problems (Anonymous, 2009). This involves a questionnaire of known risk factors which can be used to produce a prioritised risk reduction strategy at the farm level.

Bracke (2009) pointed out that to date no scientific study has ever confirmed the efficacy of tail biting treatments suggested in the literature. In a semi-automated rope test, Bracke (2009) also showed that Stockholm tar and Dippel's oil significantly reduced rope manipulation, indicating that these substances indeed act as repellents and may be effective in controlling tail biting.

Reducing tail damage is considered important by the industry. Zonderland (2010), for example, reported an overall financial cost of 8 million euro‟s associated with tail damage despite tail docking in intensive pig farming in the Netherlands. This implies about 2400 Euro‟s per year per farm with either 500 sows or 4000 fattening pigs. The calculation included estimated costs for treatment and production consequences of tail damage (with an estimated prevalence of 2.1%), disregarding the costs of docking itself and disregarding the costs of other forms of biting such as ear and flank biting (Zonderland et al., unpublished data).

The measures taken by farmers to counteract tail and ear biting may include measures that may impair welfare. These include social isolation (taking the victims and biters out of the pen), application of aversive substances to tail and ears, and (illegal) clipping of teeth (De Lauwere et al., 2009). Less than 50% of Dutch farmers reported taking out victims or biters to stop tail 97 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

biting. About 15% (14.9 – 18.3%) of Dutch farmers reported clipping the teeth of presumed/potential biters to counteract an outbreak of tail biting (De Lauwere et al., 2009). This raised public concern (EL&I, 2010, 2011) and the decision to formulate a strategy involving the Dutch ministry and farmers unions to support the phasing-out of tail docking, teeth treatments and other mutilations by 2023 in The Netherlands. The instruments used in the short term will include advice on improving husbandry circumstances. For the longer term, potential solutions lie in redesigning pig housing systems. De Greef et al. (2011) presented the proof of principle of the so-called Comfort Class system for pigs, which was specifically designed to meet the welfare needs of the pigs. Observations showed that tail and skin damages remained at, or were reduced to, a low level (depending on whether pigs already had lesions when entering the system).

5.10. Food safety considerations (E.11.) No new information

Conclusions and Recommendations This section on Conclusions and Recommendations was written by the editorial team on the basis of the evidence provided in the previous chapters.

CONCLUSIONS - ADDITIONAL CONCLUSIONS TO THE PREVIOUS EFSA REPORT

1. Tail and ear lesions (wounds, but also missing ear and tail tips) are indicative of reduced welfare (now and/or in the past). They can be detected fairly easily, even at the slaughterhouse. Healed lesions should be included in the observations (E.2.). 2. Acute lesions rapidly escalate on farm. Tail, ear, leg and flank biting are abnormal and harmful behaviours (E.3.1.). 3. While lack of enrichment is a main reason for such lesions, also a range of other factors may be involved e.g. reduced health, thermal inadequacies, problems with feed and water, etc.). All of these are associated with reduced welfare (E.8.). 4. Tail biting may arise as a result of different motivational triggers, explaining the diversity of risk factors (E.3.1.). 5. Use of group selection as a breeding strategy has the potential to reduce genetic predisposition to tail bite (E.8.1.1.). 6. Tail docking has been shown to cause pain. The length of dock may affect the degree of pain, as evidenced by neuroma formation, but must be balanced against tail biting risk which increases with tail length. Current data do not conclusively indicate the least painful method of docking (E.8.9. and E.7.). 7. Reliable behavioural signs of an impending tail biting outbreak have been identified and can be used to take precautionary measures (E.10.). 8. Measures taken by farmers to counteract tail and ear biting outbreaks also include measures that may impair welfare. These include social isolation (taking the victims and biters out of the pen), application of aversive substances to tail and ears, and clipping of teeth (E.10.). 98 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Preparatory work for pig welfare indicators – Report 2

9. Tail and ear biting behaviour (when wounds are present, but also when healed) may be treated with enhanced enrichment (e.g. ample long straw provided fresh twice daily) throughout the pig‟s life. However, other risk factors (stocking density, ventilation, feed, ...) should be investigated or audited too (E.8.3.1., E.8.5.1., E.8.5.2., E.8.6. and E.8.8.2). 10. Research to date indicates that while toys may show some reduction in tail biting, especially when they have destructible components like soft wood or destructible tubing, natural substrates such as straw or compost seem to be necessary to reduce biting problems to acceptable levels in problem pens (E.8.5.).

99 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

RECOMMENDATIONS AND ASSOCIATED HAZARDS Recommendation in previous EFSA Suggested recommendations following the present Hazard involved Relevant report (EFSA, 2005) evaluation paragraph

1. Accurate data on the entire range of Further supported by new information Tail biting E.5.1.1 deleterious effects on pig health associated with tail biting should be collated.

2. It is important to monitor the pigs closely at No change Tail biting NA times of life when husbandry is changing in order to possibly prevent tail-biting outbreaks. 3. Those housing and management procedures Further supported by new information Poor housing and Throughout this that are found to prevent tail biting should be management procedures report. applied and if tail biting occurs, such management interventions that prevent an escalation of the problem and the negative consequences of poor welfare in victim pigs should be applied. The importance of good stockmanship is emphasized. 4. Since tail-biting can cause very poor welfare Further supported by new information Pain due to tail docking E.7 and tail-docking is likely to be painful, both

Scientific Report 2 updating the EFSA opinions on the welfare of pigs

in the short term and as a result of possible long-term pain from neuroma formation, measures other than tail docking should be implemented to control tail biting and its adverse effects for welfare. 5. To minimise the risk of tail-biting, it is Further supported by new information Tail biting E.8 recommended to address the following major risk factors: (i) provision of straw, preferably as bedding, and (ii) proportion of slatted floors in housing systems for fattening pigs. Due to the severe adverse effects for pigs of tail biting inducing poor welfare, when tail biting incidence increases in a farm, other factors which have also effect on the likelihood of tail biting (e.g. air speed, health status, high temperatures) should be considered. 6. Monitoring at slaughter of lesions related to Additionally: NA E.7 tail biting is suggested as a mean to identify herds with such problems as guidance for the Monitoring at slaughter should include also tail length implementation of preventive actions. (in addition to tail lesions) as well as ear shape (missing parts of the ears) and biting wounds on flanks and legs.

7. The methodology and the results Additionally: NA E.10 (Conclusions and Recommendations) of this opinion as well as the previous opinions on An intact curly tail may well be the single most Pig Welfare, should be further analysed important animal-based welfare indicator for weaned, identifying welfare indicators (in particular growing and finishing pigs (at herd level). In addition, it animal-based) suitable for the development of stands for high-quality management and respect for the an animal welfare monitoring system. integrity of the pig.

101 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

Scientific Report 2 updating the EFSA opinions on the welfare of pigs

N1 The wealth of information on how to reduce the risk of Poor housing and Throughout this tail biting (such as providing suitable enrichment, management report. ensuring a good thermal environment and appropriate feeding) without docking pig tails, should be used to underpin the importance of preventative measures.

Long term strategies to reduce tail biting should be NA E.10. aimed at changing the housing situation for pigs by developing new systems which support the behavioural needs of the animals as well as good farm economic performance.

102 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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105 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.

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106 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. The present document is published complying with the transparency principle to which the European Food Safety Authority is subject. It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors.