Brscic Marta, Dam Otten Nina, Contiero Barbara, Kirchner Marlene Katharina
Department of Animal Medicine, Production and Health, University of Padova, 35020 Legnaro (PD), Italy.
Institute of Animal Welfare and Disease Control, Dep. Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark.
Animals (Basel). 2019 Oct 2;9(10):757. doi: 10.3390/ani9100757.
Assessing emotional states of dairy calves is an essential part of welfare assessment, but standardized protocols are absent. The present study aims at assessing the emotional states of dairy calves and establishing a reliable standard procedure with Qualitative Behavioral Assessment (QBA) and 20 defined terms. Video material was used to compare multiple observer results. Further, live observations were performed on 49 dairy herds in Denmark and Italy. Principal Component Analysis (PCA) identified observer agreement and QBA dimensions (PC). For achieving overall welfare judgment, PC1-scores were turned into the Welfare Quality (WQ) criterion 'Positive Emotional State'. Finally, farm factors' influence on the WQ criterion was evaluated by mixed linear models. PCA summarized QBA descriptors as PC1 'Valence' and PC2 'Arousal' (explained variation 40.3% and 13.3%). The highest positive descriptor loadings on PC1 was Happy (0.92) and Nervous (0.72) on PC2. The WQ-criterion score (WQ-C12) was on average 51.1 ± 9.0 points (0: worst to 100: excellent state) and 'Number of calves', 'Farming style', and 'Breed' explained 18% of the variability of it. We conclude that the 20 terms achieved a high portion of explained variation providing a differentiated view on the emotional state of calves. The defined term list proved to need good training for observer agreement.
评估奶牛犊牛的情绪状态是福利评估的重要组成部分，但目前尚无标准化方案。本研究旨在评估奶牛犊牛的情绪状态，并通过定性行为评估（QBA）和20个定义术语建立可靠的标准程序。使用视频资料比较多个观察者的结果。此外，还对丹麦和意大利的49个奶牛群进行了现场观察。主成分分析（PCA）确定了观察者之间的一致性和QBA维度（主成分）。为了实现整体福利判断，将主成分1（PC1）得分转化为福利质量（WQ）标准中的“积极情绪状态”。最后，通过混合线性模型评估农场因素对WQ标准的影响。PCA将QBA描述符总结为主成分1“效价”和主成分2“唤醒度”（解释变异分别为40.3%和13.3%）。主成分1上最高的正向描述符载荷是“快乐”（0.92），主成分2上是“紧张”（0.72）。WQ标准得分（WQ-C12）平均为51.1±9.0分（0分：最差至100分：最佳状态），“犊牛数量”、“养殖方式”和“品种”解释了其18%的变异性。我们得出结论，这20个术语实现了较高比例的解释变异，为犊牛情绪状态提供了差异化的视角。事实证明，为达成观察者之间的一致性，所定义的术语列表需要进行良好的培训。
