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A Systematic Evaluation of Laying Hen Housing for Improved Hen Welfare Angela Renee Green Iowa State University

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A Systematic Evaluation of Laying Hen Housing for Improved Hen Welfare Angela Renee Green Iowa State University Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 2008 A systematic evaluation of laying hen housing for improved hen welfare Angela Renee Green Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Agriculture Commons, Animal Sciences Commons, Bioresource and Agricultural Engineering Commons, Physiology Commons, and the Veterinary Physiology Commons Recommended Citation Green, Angela Renee, "A systematic evaluation of laying hen housing for improved hen welfare" (2008). Retrospective Theses and Dissertations. 15861. https://lib.dr.iastate.edu/rtd/15861 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. A systematic evaluation of laying hen housing for improved hen welfare by Angela Renee Green A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Agricultural Engineering (Agricultural Structures and Environmental Systems) Program of Study Committee: Hongwei Xin, Major Professor Dianne Cook Jay Harmon Steve Hoff Anna Johnson Iowa State University Ames, Iowa 2008 Copyright © Angela Renee Green, 2008. All rights reserved. UMI Number: 3296796 UMI Microform 3296796 Copyright 2008 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, MI 48106-1346 ii Table of Contents List of Tables ......................................................................................................................v List of Figures .................................................................................................................. viii Acknowledgements............................................................................................................ xi Chapter 1: General Introduction ..........................................................................................1 Laying Hen Housing Systems..................................................................................1 Regulations Concerning Laying Hen Housing ........................................................3 Need for Systematic Approach to Evaluating and Assessing Hen Housing............7 Statement of the Issue ..............................................................................................9 Objectives and Organization of the Dissertation .....................................................9 Expected Outcomes and Practical Implications.....................................................10 References..............................................................................................................11 Chapter 2: Current and Emerging Housing Systems for Laying Hens – A Literature Review ......................................................................................................14 Introduction............................................................................................................14 Confinement Methods of Modern Commercial Laying-Hen Housing..................19 Management Considerations for the Housing Systems .........................................25 Welfare Considerations for Housing Systems .......................................................32 Economic Considerations for Housing Systems....................................................44 Food Safety............................................................................................................47 Summary of System Comparisons.........................................................................49 Identified Gaps for Future Research......................................................................51 References..............................................................................................................53 Chapter 3: Field Evaluation of Air Quality and Bird Health Status in Three Types of Commercial Egg Layer Houses .................................................................77 Abstract..................................................................................................................77 Introduction............................................................................................................78 iii Materials and Methods...........................................................................................81 Results and Discussion ..........................................................................................84 Conclusions and Applications ...............................................................................90 References..............................................................................................................92 Chapter 4: Effects of Stocking Density and Group Size on Laying Hens: Part I – Bioenergetics, Production, and Hen Condition under Thermoneutral and Heat Challenge Conditions ...............................................................106 Abstract................................................................................................................106 Introduction..........................................................................................................107 Materials and Methods.........................................................................................109 Results ..................................................................................................................114 Discussion............................................................................................................116 Conclusions..........................................................................................................120 References............................................................................................................122 Appendix A: Equations for calculation of heat and moisture production by indirect calorimetry..................................................................................144 Chapter 5: Effects of Stocking Density and Group Size on Laying Hens: Part II – Microenvironment and Thermoregulatory Responses under Thermoneutral and Heat Challenging Conditions ...................................146 Abstract................................................................................................................146 Introduction..........................................................................................................147 Materials and Methods.........................................................................................149 Results ..................................................................................................................152 Discussion............................................................................................................154 Conclusions..........................................................................................................156 References............................................................................................................157 iv Chapter 6: Development of a Novel Environment Preference Test System for Laying Hens and Its Initial Application to Assess Hen Aversion to Atmospheric Ammonia............................................................................167 Abstract................................................................................................................167 Introduction..........................................................................................................168 Materials and Methods.........................................................................................169 Results ..................................................................................................................176 Discussion............................................................................................................177 Conclusions..........................................................................................................180 References............................................................................................................182 Chapter 7: Summary and Implications ............................................................................198 v List of Tables Table 2.1: Comparison of advantages and disadvantages of current and emerging housing systems for laying-hen production, assuming properly designed, well-managed facilities..............................................................72 Table 3.1: Description of the laying hen houses monitored ..............................................97 Table 3.2: Winter conditions: 24 h mean, maximum and minimum values for each laying-hen house and resulting overall mean and standard error for each type of housing system. .....................................................................98 Table 3.3: Summer conditions: 24 h mean, maximum and minimum values for each house and resulting overall mean and standard error for each type of housing system...........................................................................................99
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