Park Janice Y, Campler Magnus R, Cheng Ting-Yu, Youngblood Brad L, Torrisi Dawn, Cressman Michael D, Kieffer Justin D, Williams Todd E, Arruda Andréia G, Flory Gary A, Hougentogler Daniel P, Hill Jeff, Hunt Lucia, Canturri Albert, Culhane Marie R, Miller Jesse, Bowman Andrew S
Department of Veterinary Preventive Medicine, The College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States of America.
Office of the Attending Veterinarian, The Enterprise for Research, Innovation and Knowledge, The Ohio State University, Columbus, Ohio, United States of America.
PLoS One. 2025 Mar 25;20(3):e0320217. doi: 10.1371/journal.pone.0320217. eCollection 2025.
The threat of foreign animal disease outbreaks to U.S. swine herds warrants effective and readily available depopulation methods. Current American Veterinary Medical Association-recommendations using preferred physical methods for swine depopulation are unsuitable for large commercial swine herds. Our objectives were to assess and compare the efficacy and performance of three suggested large-scale depopulation methods: 1) medium-expansion water-based foam, 2) prototype high-expansion nitrogen foam and, 3) carbon dioxide gas for finisher pigs under field conditions. Out of 793 finisher pigs included in the study, 84 were implanted with bio-loggers recording electrocardiogram and pig movement data. Aversive pig behaviors were collected manually on a group level for each depopulation method. A subsample of pigs from each method were examined post-mortem for lesions and compared to a reference group of nine pigs euthanized with pentobarbital. Depopulation method assessments included container fill time, the number of aversive pig behaviors observed during depopulation, overall pig movement intensity, time to cessation of movement, time to and cause of cardiac arrest, and respiratory lesions. No difference in fill times between water-based foam and nitrogen foam was observed. The total number of aversive swine behaviors was higher for carbon-dioxide compared to both foam methodologies (P < 0.01). The total pig activity was higher in water-based foam compared to nitrogen foam (P = 0.02) and carbon-dioxide methods (P = 0.01). The mean time to cessation of movement was significantly shorter for water-based foam and nitrogen foam compared to carbon-dioxide (P < 0.01). No differences in cardiac activity were observed. Water-based foam pigs had increased odds of distal trachea occlusions compared to other methods. All depopulation methods demonstrated high efficacy with a 100% mortality rate. The results from this study support large-scale water-based foam, nitrogen foam and carbon dioxide as viable AVMA depopulation guideline candidates for swine.
外来动物疾病爆发对美国猪群构成的威胁，使得有效的、随时可用的猪群扑杀方法成为必要。美国兽医协会目前推荐的使用首选物理方法进行猪群扑杀，并不适用于大型商业养猪场。我们的目标是评估和比较三种建议的大规模扑杀方法的效果和性能：1）中膨胀水基泡沫，2）原型高膨胀氮气泡沫，以及3）用于育肥猪的二氧化碳气体，实验在实地条件下进行。在该研究纳入的793头育肥猪中，84头被植入了记录心电图和猪运动数据的生物记录器。针对每种扑杀方法，在群体层面人工收集猪的厌恶行为。对每种方法的猪样本进行死后检查以确定病变情况，并与9只用戊巴比妥安乐死的猪组成的参考组进行比较。扑杀方法评估包括容器填充时间、扑杀过程中观察到的猪的厌恶行为数量、猪的总体运动强度、停止运动的时间、心脏骤停的时间和原因，以及呼吸道病变。未观察到水基泡沫和氮气泡沫在填充时间上的差异。与两种泡沫方法相比，二氧化碳导致的猪的厌恶行为总数更高（P < 0.01）。与氮气泡沫（P = 0.02）和二氧化碳方法（P = 0.01）相比，水基泡沫中的猪的总体活动更高。与二氧化碳相比，水基泡沫和氮气泡沫使猪停止运动的平均时间显著更短（P < 0.01）。未观察到心脏活动方面的差异。与其他方法相比，水基泡沫处理的猪出现远端气管阻塞的几率更高。所有扑杀方法均显示出高效，死亡率达100%。本研究结果支持将大规模水基泡沫、氮气泡沫和二氧化碳作为美国兽医协会可行的猪群扑杀指南候选方法。
