Effectiveness of a Non-penetrating Captive Bolt for Euthanasia of Suckling and Weaned Piglets by Teresa Casey-Trott A Thesis Presented to The University of Guelph In partial fulfillment of requirements for the degree of Master of Science in Animal and Poultry Science Guelph, Ontario, Canada © Teresa Marie Casey-Trott, August, 2012 ABSTRACT EFFECTIVENESS OF A NON-PENETRATING CAPTIVE BOLT FOR EUTHANASIA OF SUCKLING AND WEANED PIGLETS Teresa Marie Casey-Trott Advisor: University of Guelph, 2012 Professor Tina M. Widowski There has been minimal research into the most humane, practical method for on-farm euthanasia of suckling and weaned piglets. The goal of the research presented in this thesis was to test the effectiveness of a non-penetrating captive bolt (Zephyr-E) for euthanasia of piglets ≤ 9 kg. Brainstem and spinal reflexes and heartbeat were used to determine the time to insensibility and death. Post-mortem damage was scored to assess the degree of traumatic brain injury (TBI) induced by the Zephyr-E. The Zephyr-E consistently resulted in immediate, sustained insensibility until death in piglets ≤ 9 kg. Skull fractures and subdural and parenchymal hemorrhage were present in all piglets. Neonatal piglets had longer durations of convulsions and heartbeat and more severe damage than weaned piglets, suggesting age and weight effect TBI. Overall, the Zephyr-E was a highly effective, single step method of euthanasia for suckling and weaned piglets up to 9 kg. iii ACKNOWLEDGEMENTS First and foremost, I would like to thank my advisor, Dr. Tina Widowski, for her support, patience, and guidance as I learned what it takes to earn a Masters degree. Her confidence in me encouraged me to push my boundaries and get the most out of this experience. I cannot imagine a better advisory match for me. Thank you to my committee members Drs. Suzanne Millman, Pat Turner, and Leah Bent as well as Dr. Stephanie Nykamp for offering their time, resources, and expertise. Thank you to Dr. Margaret Quinton and Michelle Edwards, who provided me with the tools and confidence to understand statistics and SAS coding. This work would not have been possible without the help of a long list of co-workers, volunteers, and research teams in Ontario, Iowa, and Saskatchewan. Their positive attitudes and willingness to learn helped ease the stress of a sometimes emotionally challenging task. Thank you to all the producers and stock personnel who opened their doors to me and my research team to spend the morning focusing on a difficult topic. Their unrestricted feedback and first-hand experience helped me to gain a better understanding of the swine industry and reminded me that my research topic affected the welfare of humans as well as animals. Lastly, I would like to thank my family and friends who convinced me that I could take on this challenging topic with the appropriate balance of science and empathy. Thank you to my animals who gave me simple chores to accomplish at the end of the day when it felt like the writing stage was futile. Thank you to my son James who helped me to forget that I had work to do, and remember that there is so much more to life. Finally, I would like to thank my dedicated husband, David, who took on countless extra responsibilities to allow me to pursue this path. With his unfailing love and support, I look forward to our next adventure. iv TABLE OF CONTENTS Acknowledgements ..................................................................................................................... iii Table of Contents ........................................................................................................................ iv List of Tables ............................................................................................................................... vi List of Figures ............................................................................................................................ viii Chapter 1 .......................................................................................................................................1 INTRODUCTION Swine Industry Overview .........................................................................................................2 Causes of Pre-weaning Piglet Mortality ..............................................................................3 Weaned and Nursery Piglet Morality ..................................................................................4 Chapter 2 .......................................................................................................................................6 LITERATURE REVIEW Welfare Concerns Associated with Euthanasia ......................................................................6 Consciousness in the Mammalian Brain ..................................................................................7 Assessing Insensibility and Time of Death ..............................................................................8 Euthanasia Methods and Modes of Action .............................................................................11 Acceptable Euthanasia Techniques for Piglets ..................................................................12 Non-Inhalant Pharmaceuticals ...........................................................................................13 Anesthetic Overdose...............................................................................................13 Gaseous Inhalants ..............................................................................................................13 Carbon Dioxide ......................................................................................................13 Physical Methods ...............................................................................................................15 Electrocution ..........................................................................................................16 Manual Blunt Force Trauma .................................................................................17 Gunshot ..................................................................................................................18 Captive Bolt Guns ..................................................................................................19 Traumatic Brain Injury from BFT and NPCB ........................................................................21 Research Objectives ...............................................................................................................24 v Chapter 3 ......................................................................................................................................25 Effectiveness of a Non-Penetrating Captive Bolt for Euthanasia of Piglets < 3 Days of Age 3.1 Abstract ............................................................................................................................25 3.2 Introduction ......................................................................................................................27 3.3 Methods ............................................................................................................................28 3.4 Results ..............................................................................................................................34 3.5 Discussion .........................................................................................................................37 Chapter 4 .....................................................................................................................................53 Effectiveness of a Non-penetrating Captive Bolt for Inducing Cardiac Arrest in Anesthetized Piglets Ranging from 3 to 9 kg 3.1 Abstract ............................................................................................................................53 3.2 Introduction ......................................................................................................................54 3.3 Methods ............................................................................................................................56 3.4 Results ..............................................................................................................................59 3.5 Discussion .........................................................................................................................61 Chapter 5 .....................................................................................................................................75 Effectiveness of a Non-Penetrating Captive Bolt for Euthanasia of Piglets Ranging from 3 to 9 kg 3.1 Abstract ............................................................................................................................75 3.2 Introduction ......................................................................................................................76 3.3 Methods ............................................................................................................................78 3.4 Results ..............................................................................................................................82 3.5 Discussion .........................................................................................................................84 Chapter 6 ...................................................................................................................................107