Agriculture, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK.
Zoetis International, Cherrywood, Loughlinstown, Dublin, Ireland.
J Anim Sci. 2019 Apr 29;97(5):1956-1966. doi: 10.1093/jas/skz083.
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.
疾病是导致猪系统福利和生产力下降的主要原因，但通过早期检测，可以限制其在商业群体中的传播。在疾病发作时识别特定的行为变化，可以通过及时干预提高治疗成功率，从而具有重要的诊断价值。我们的研究旨在确定在少数个体急性患病时，群体水平上可见的关键行为变化。首先，我们使用全圈接种作为人为疾病模型，量化了猪群在急性健康挑战期间的行为变化。然后，我们研究了在三种处理方式下（对照（Con；0%的猪）、低（±20%的猪）或高（±50%的猪）接种的猪）检测群体水平行为变化所需的患病猪的最小比例。试验 1 中的全圈接种导致了群体水平的行为变化，包括减少采食（P < 0.001）、非营养性地访问料槽（P < 0.01）、饮水（P < 0.001）、站立（P < 0.001）和与圈舍丰容的互动（P < 0.001），同时增加躺卧率（P < 0.01）和体温升高（P < 0.001），证实接种是研究急性疾病影响的合适模型。在试验 2 中，与丰容设备的互动（P < 0.001）和站立率（P = 0.064）的群体水平下降，以及圈舍躺卧率的增加（P < 0.001），在低处理组中与对照率相比，这表明这些关键行为可能对群体中早期疾病检测具有重要的诊断价值。这些变化持续了接种后 3 小时。相比之下，在高处理组中，只有在接种后，采食率（处理×时间：P < 0.01）才会从对照率下降，而圈舍饮水则呈现出类似的趋势（处理：P = 0.07），这表明这些行为更适合确认疾病在猪群中的传播。确定提示疾病存在的关键行为对于使用圈舍级传感器进一步完善商业养猪场的自动预警系统至关重要。
