Review of the scientific literature and the international pig welfare codes and standards to underpin the future Standards and Guidelines for Pigs Final Report APL Project 2017/2217 August 2018 Animal Welfare Science Centre, University of Melbourne Dr Lauren Hemsworth Prof Paul Hemsworth Ms Rutu Acharya Mr Jeremy Skuse 21 Bedford St North Melbourne, VIC 3051 1 Disclaimer: APL shall not be responsible in any manner whatsoever to any person who relies, in whole or in part, on the contents of this report unless authorised in writing by the Chief Executive Officer of APL. Table of Contents Executive Summary .................................................................................................................... 3 1. Animal welfare and its assessment ...................................................................................... 12 2. Purpose of this Review and the Australian Model Code of Practice for the Welfare of Animals – Pigs .......................................................................................................................... 19 3. Housing and management of pigs ....................................................................................... 22 3.1 Gestating sows (including gilts) ......................................................................................... 23 3.2 Farrowing/lactating sow and piglets, including painful husbandry practices ................... 35 3.3 Weaner and growing-finishing pigs ................................................................................... 60 3.4 Boars .................................................................................................................................. 70 3.5 Outdoor housing ................................................................................................................ 72 4. Specific physiological and behavioural problems in pigs ..................................................... 76 5. General management practices of pigs ............................................................................ 86 6. Human resource management ....................................................................................... 103 7. Mitigation of risk in emergency situations ..................................................................... 109 8. References ...................................................................................................................... 111 2 Executive Summary All pigs farmed in Australia are governed by the Australian Model Code of Practice for the Welfare of Animals – Pigs, which was approved by the Primary Industries Ministerial Council on April 2007. The original Model Code of Practice was approved by the Australian Agricultural Council in 1989 and the code has been subsequently updated in 1998, 2001, 2004 and 2007 to incorporate the latest research findings and new technologies in the area. This review is a comprehensive documentation of recent findings on pig welfare at all stages of their production cycle. Furthermore, comparisons are made between the current Australian Model Code of Practice for the Welfare of Animals – Pigs and the current Codes or Standards in Canada (Code of Practice for the Care and Handling of Pigs, 2014), the United Kingdom (UK, Codes of Recommendations for the Welfare of Livestock: Pigs, 2002), the European Union (EU, Council Directive 2008/120/EC) and New Zealand (Pigs – Animal Welfare Code of Welfare, 2018). These countries were selected because their high standards of pig welfare have been widely recognised. Pig farming is one of the most intensive of all the livestock production systems; animals are commonly housed in large buildings, with a high degree of automation to supply feed, water, heat and ventilation. Whilst the increased intensification of animal production methods has reduced or removed a range of welfare problems, such as predation, thermal stress, some infectious diseases and nutritional stress, it has also created or exacerbated other welfare problems such as restricted space and social contact, lameness and barren environments. Extensive livestock production systems are generally thought to be less restrictive, however they do still impose restrictions on animals, albeit with considerable freedom and there are different welfare risks including frequency of inspections, climatic conditions and natural disasters. All aspects of pig production are attracting welfare concerns; sow housing, growing-finishing pig housing, transport and slaughter. In pig production, the most contentious welfare issues involve indoor housing (close confinement and barren environment), particularly of breeding sows, however potential welfare issues do also exist in outdoor pig systems, including the implications of nose-ringing, shelter, litter desertion, pre-weaning piglet mortality, wallow design and management, thermoregulation in winter, heat stress in summer, any implications of lower back fat, and the suitability of different genotypes. The following review provides conclusions, recommendations and future research for the following issues relevant to the Australian pig industry: Gestating sows (including gilts) 3 • There are some obvious gaps in our knowledge on safeguarding the welfare of gestating sows and these obviously are topics for future research. • The most obvious weakness in our knowledge on safeguarding the welfare of gestating sows is strategies for effective environmental enrichment in intensive, indoor and non-bedded systems. Together with the practice of restricted feeding of gestating sows, strategies for example to increase foraging and feeding times in feed-restricted gestating sows will reduce hunger and the likely development of oral stereotypies. • Research on space allowance indicates that a space allowance for gilts and sows of 1.4 m2/animal is likely to be too small and that significant improvements in welfare, in terms of aggression and stress, are likely to be achieved with space allowances for gilts and sows in the range of 2.0–2.4 m2/animal. • The effects of space on aggression and stress are most pronounced soon after mixing, highlighting the importance of floor space at mixing. Indeed, a strategy of staged gestation penning, with more space immediately after mixing and less space later in gestation may provide distinct animal welfare and economic advantages, but this requires investigation. • While floor feeding is generally viewed as the most competitive feeding system, accessing feeding stalls or an electronic sow feeder (ESF) system also leads to competition between group-housed sows. A better appreciation of the positioning of resources and barriers in pens to facilitate access to important resources, such as feed, water and a comfortable lying area, and allow escape opportunities from others, is important in reducing aggression and stress and thus minimise risks to sow welfare. Research recommendations: areas for future research to safeguard gestating sow welfare include effective environmental enrichment for gestating sows in intensive, indoor and non-bedded systems; opportunities to increase foraging (which clearly also provides environment enrichment); feeding times in feed-restricted gestating sows; and the use of stage gestation penning. S&G recommendations: increasing the space allowance guidelines for gilts and sows in the range of 2.0–2.4 m2/animal is likely to result in significant improvements in welfare (and productivity) with regard to aggression and stress. It is also important to monitor ongoing research investigating effective environmental enrichment for intensive, indoor and non-bedded systems in order to use outcomes to inform S&G on enrichment for not only gestating sows but pigs in all stages of production. Farrowing/lactating sow and piglets, including painful husbandry practices 4 • Housing pre-parturient sows in farrowing crates without bedding/nesting material reduces their level of maternal behaviour in comparison to sows in more enriched environments. • While confining sows, at least primiparous sows, at farrowing and/or denying them access to bedding/nesting material may induce acute stress, the limited evidence suggests that housing sows in farrowing crates without bedding is not a potent stressor for at least 3 weeks of lactation. However, housing beyond 3 weeks of lactation in farrowing crates may be stressful for sows. • Alternative loose farrowing and lactation environments can provide sows with bedding and thus increased opportunity to perform maternal behaviours (including nest building and interaction with their piglets). However, these loose farrowing and lactation systems require extra floor space and can lead to an increased risk of piglet crushing. • Total overall piglet losses (stillbirths and live born deaths) may be similar with loose farrowing and lactation pens and farrowing crates, however crushing of live born piglets is often higher in loose pens. • Many causes of piglet mortality are a welfare concern because asphyxiation, starvation and physical trauma are likely to lead to negative affective states such as pain, fear and suffering. • Piglets that develop full breathing but descend quickly into hypothermia and thus unconsciousness and, to a lesser extent, piglets that never develop full breathing are less of a welfare concern. However, piglets that develop full breathing, are not hypothermic, but suffer deaths from hunger, injury or disease are a greater welfare concern. Thus, any farrowing and lactation housing system needs