Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA.
Department of Animal Sciences, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Columbus, Ohio, USA.
Transbound Emerg Dis. 2022 Sep;69(5):e2719-e2730. doi: 10.1111/tbed.14622. Epub 2022 Jun 22.
Animal disease preparedness plans including depopulation guidelines are paramount to prevent the spread of emerging infectious diseases but difficult to implement for swine under field conditions. However, water-based foam (WBF) is currently an approved and successfully deployed depopulation methodology in poultry. Therefore, the reliability of WBF as a depopulation method and the effectiveness and irreversibility of consciousness and consequential mortality in pigs of different ages was assessed across two trials. Trial 1 investigated the time to loss of consciousness and cessation of cardiac activity in nursery pigs (n = 72) at six different foam immersion time points (2.5, 5, 7.5, 10, 12.5 and 15 min) when placed in a 1.47 m (1.2 × 1.2 × 1.02 m, length × width × height) plastic bulk container. One pig per replicate was implanted with an ECG bio-logger. Irreversible loss of consciousness was observed after a 5-min immersion. The average (SD) time to development of a fatal arrhythmia from the initiation of the foam application was 7.3 min (1.82 s). Trial 2 aimed to validate the findings from Trial 1 in 75 larger cull sows across three replicates (n = 25). Sows were loaded into a 41-m sealed trailer (12.2 × 1.5 × 2.24 m), immersed in WBF and left undisturbed for 5 min post foam-filling completion. Six pigs in each replicate were implanted with an ECG bio-logger. A 5-min dwell time resulted in irreversible loss of consciousness and subsequent mortality in all cull sows. The average time (SD) to cessation of movement and fatal arrhythmia post foam-filling completion was 2.2 min (34.8 s) and 8.7 min (138.0 s), respectively. While a 5-min immersion in WBF induced irreversible loss of consciousness and death in both trials, a 7.5-min dwell time followed by observation for confirmation of death post WBF removal would be advisable for pigs of all sizes.
动物疾病预备计划包括扑杀指南对于防止新发传染病的传播至关重要，但在野外条件下对猪实施这些计划却很困难。然而，水基泡沫 (WBF) 目前是一种已批准并成功用于家禽扑杀的方法。因此，在两项试验中评估了 WBF 作为扑杀方法的可靠性，以及不同年龄的猪在意识丧失和随后死亡方面的效果和不可逆性。试验 1 研究了在将 72 头保育猪放入 1.47 米（1.2×1.2×1.02 米，长×宽×高）的塑料散装容器中进行六个不同的泡沫浸泡时间点（2.5、5、7.5、10、12.5 和 15 分钟）时，失去意识和心脏活动停止的时间，每个重复中有一头猪植入了心电图生物记录器。浸泡 5 分钟后观察到不可逆的意识丧失。从泡沫应用开始到致命心律失常发展的平均（SD）时间为 7.3 分钟（1.82 秒）。试验 2 的目的是在三个重复中（n=25）验证试验 1 的结果，使用 75 头较大的淘汰母猪进行验证。母猪被装入一个 41 米的密封拖车（12.2×1.5×2.24 米）中，浸入 WBF 中，在泡沫填充完成后不干扰 5 分钟。每个重复中有 6 头猪植入了心电图生物记录器。在所有淘汰母猪中，5 分钟的停留时间导致不可逆的意识丧失和随后的死亡。从泡沫填充完成到停止运动和致命心律失常的平均时间（SD）分别为 2.2 分钟（34.8 秒）和 8.7 分钟（138.0 秒）。虽然在两项试验中，5 分钟的 WBF 浸泡都会导致不可逆的意识丧失和死亡，但对于所有大小的猪，建议在 7.5 分钟的停留时间后，观察确认 WBF 去除后的死亡情况。
