Amy L. Miller，Hillary A. Dalton，Theo Kanellos，Ilias Kyriazakis 翻译：朱滔 校对：上海亘泰实业集团 疾病是影响猪只生产效率和动物福利的主要因素之一，但是早期诊断可以有效控制疾病在猪群内的传播。通过定期巡视，在疾病初发阶段识别特定的行为变化，可以改善治疗效果，从而带来更好的诊断结果。 本试验目的在于确定少数猪只生病时可观察到的变化的关键群体行为。首先，大家通过全圈接种作为人工致病模型，确定在急性健康攻毒条件下哪些猪群行为发生了变化。然后大家通过三个处理组来研究引起群体行为变化所需要的最少生病猪只数量。处理组包括：对照组、低接种组（±20%猪）、高接种组（±50%猪）。 试验一中全群接种引起了群体行为的变化，包括降低采食（P＜0.001）、非营养性的访问料槽（P＜0.01）、饮水（P＜0.001）、站立（P＜0.001）和圈舍玩具互动（P＜0.001），同时躺卧率（P＜0.01）和体温（P＜0.001）都有显著提高，证明接种是研究急性病情的合适模型。 试验二，与对照组相比，低接种组圈舍玩具互动、站立率显著降低（P＜0.001；P=0.064），躺卧率显著提高，这表明这些关键行为可以为群体疾病早期发现提供重要的诊断价值。这些行为的变化可以持续到接种后的3h。但是，采食率（处理×时间：P＜0.01）只有在高接种组表现明显，饮水也是同样的趋势（P=0.07），说明这些行为可能更合适作为疾病在群体传播的证据。 疾病相关的关键行为的鉴别对于进一步利用圈舍传感器为商业养殖场开发早期自动警报系统十分关键。
How many pigs within a group need to be sick to lead to a diagnostic change in the group’s behavior?
Disease is a leading cause of diminished welfare and productivity in pig systems, but its spread among pigs within commercial herds can be limited through early detection. Identifying specific behavioral changes at the onset of disease can have a substantial diagnostic value by improving treatment success through timely intervention. Our study aimed to identify key behaviors that visibly change at the group level when only a few individuals are acutely sick. First, we quantified the behavioral changes seen during an acute health challenge in groups of pigs, using total pen vaccination as an artificial sickness model. Then we investigated the minimum proportion of sick pigs needed to detect group level behavioral changes using three treatments: a control (Con; 0% pigs), low (±20% pigs), or a high (±50% pigs) number of pigs vaccinated in the pens. Total pen vaccination in Trial 1 produced group level behavioral changes, including reduced feeding (P < 0.001), non-nutritive visits to the feeder (P < 0.01), drinking (P < 0.001), standing (P < 0.001), and interaction with pen enrichment (P < 0.001), accompanied by increased lying rates (P < 0.01) and elevated body temperatures (P < 0.001), confirming that vaccination is an appropriate model to study effects of acute sickness. In Trial 2, group level declines in interaction with the enrichment device (P< 0.001) and standing rates (P = 0.064), along with an increase in pen lying rates (P < 0.001), were apparent in the Low treatment when compared to the Con rates, which suggests these key behaviors could serve an important diagnostic value for early disease detection in groups. These changes lasted for up to 3 h post vaccination. In contrast, feeding rates (treatment × time of day: P < 0.01) only showed a decrease from the Con in the High treatment after vaccination, with pen drinking showing a similar trend (treatment: P = 0.07), suggesting that these behaviors would be more appropriate for confirming the spread of disease within a herd. Identifying key behaviors that alert to the presence of disease is critical to further refine automated early warning systems using pen level sensors for commercial pig operations.（转自公众号：猪营养国际论坛）