Bus Jacinta D, Franchi Guilherme A, Boumans Iris J M M, Te Beest Dennis E, Webb Laura E, Jensen Margit Bak, Pedersen Lene Juul, Bokkers Eddie A M
Animal Production Systems group, Wageningen University and Research, P.O. Box 338, Wageningen 6700AH, the Netherlands.
Department of Animal and Veterinary Sciences, Aarhus University, Blichers Allé 20, Tjele 8830, Denmark.
Prev Vet Med. 2025 Sep;242:106555. doi: 10.1016/j.prevetmed.2025.106555. Epub 2025 May 5.
Using sensors, the health and welfare of growing-finishing pigs can be continuously monitored by detecting deviations from pigs' normal behaviour, but the validity of such algorithms requires improvement. As changes in the environment influence pig behaviour, monitoring temporal changes in environmental factors may help identify periods with a higher risk of welfare issues. The real-time relationships between pig welfare and many environmental factors are, however, not well-understood. This study examined the short-term associations of ambient ammonia with indicators of pig production and health. Ambient ammonia concentrations were monitored with sensors during the growing-finishing period of three rounds at a German (farm G, n = 110 pigs/round) and one round at a Danish farm (farm D, n = 144 pigs). Body weight was estimated daily using 3D cameras (both farms), feed intake was recorded using electronic feeding stations (only farm G), and health indicators were recorded during twice- (farm G) or thrice-weekly (farm D) farm visits. Using splines (generalised additive models), ammonia concentrations were linked to indicators of pig production and health in real time and, for body weight, at a lag of 1, 2, 3 and 7 d. We found a range of relationships between ambient ammonia (5 - 50 ppm) and production or health indicators (i.e. body weight (real-time and lagged), feed intake, coughing, sneezing, pen fouling, diarrhoea, and tear staining), but they were highly inconsistent between farms and pig rounds. Part of this inconsistency may be due to differences in manure management and sensor locations, or could be explained by age or seasonal effects (e.g. heat stress). More robust relationships were identified for clinical measures related to pig behaviour, where tail damage and skin lesions linearly increased with ammonia from low concentrations (5 - 10 ppm) onwards, hence suggesting more tail biting and aggression at higher ammonia concentrations. In conclusion, ambient ammonia did not clearly associate with pig performance and health in the short term, while higher ammonia concentrations were related to higher occurrences of clinical signs reflecting undesirable behaviours. Therefore, daily ammonia measurements using sensors may be of limited value in identifying health issues in pigs, but they may aid in detecting periods with high risk of aggressive or tail biting behaviours that require interventions. As ambient ammonia was confounded with other environmental measurements, such as ambient temperature or carbon dioxide concentrations, identified associations should be interpreted cautiously or with ammonia as general indicator of air quality.
通过传感器，可以通过检测生长育肥猪正常行为的偏差来持续监测其健康和福利状况，但此类算法的有效性仍需改进。由于环境变化会影响猪的行为，监测环境因素的时间变化可能有助于识别福利问题风险较高的时期。然而，猪福利与许多环境因素之间的实时关系尚未得到很好的理解。本研究考察了环境氨与猪生产和健康指标之间的短期关联。在德国一个农场（农场G，每轮110头猪）的三个生长育肥周期以及丹麦一个农场（农场D，144头猪）的一个周期内，使用传感器监测环境氨浓度。两个农场均使用3D摄像头每日估计体重，农场G使用电子饲喂站记录采食量，在农场每周两次（农场G）或三次（农场D）的巡查期间记录健康指标。使用样条函数（广义相加模型），将氨浓度实时与猪生产和健康指标关联起来，对于体重，则关联滞后1、2、3和7天的指标。我们发现环境氨（5 - 50 ppm）与生产或健康指标（即体重（实时和滞后）、采食量、咳嗽、打喷嚏、栏舍污染、腹泻和泪斑）之间存在一系列关系，但农场和猪群之间差异很大。这种不一致部分可能是由于粪便管理和传感器位置的差异，或者可以用年龄或季节效应（如热应激）来解释。对于与猪行为相关的临床指标，发现了更稳健的关系，即从低浓度（5 - 10 ppm）开始，尾巴损伤和皮肤病变随氨浓度线性增加，这表明在较高氨浓度下有更多的咬尾和攻击行为。总之，环境氨在短期内与猪的生产性能和健康没有明显关联，而较高的氨浓度与反映不良行为的临床症状发生率较高有关。因此，使用传感器每日测量氨浓度在识别猪的健康问题方面可能价值有限，但可能有助于检测需要干预的攻击或咬尾行为风险较高的时期。由于环境氨与其他环境测量值（如环境温度或二氧化碳浓度）相互混淆，因此应谨慎解释所确定的关联，或将氨作为空气质量的一般指标来解释。
