Phelipon Romane, Bertrand Léa, Jardat Plotine, Reigner Fabrice, Lewis Kate, Micheletta Jérôme, Lansade Léa
INRAE, CNRS, Université de Tours, PRC, Nouzilly, France.
UEPAO, INRAE, Nouzilly, France.
PLoS One. 2025 May 14;20(5):e0319315. doi: 10.1371/journal.pone.0319315. eCollection 2025.
The welfare of an animal is closely linked to their emotional experiences, making it essential to identify reliable indicators of these emotions. This study aimed to identify behaviours and facial movements in horses experiencing contrasting emotional valence, triggered by the anticipation of a positive condition (going to pasture) or a negative condition (going alone to a novel environment). Twenty horses were daily trained to wait in a starting box before being exposed to these two conditions. After one week of positive training or negative training, we analysed horses' behaviours, cortisol variations, and facial movements while they waited in their starting box. First, we confirmed that the two conditions induced contrasting emotional valence, as evidenced by the shorter time taken to approach in the positive condition compared to the negative, and by the higher maximal heart rate and cortisol variation in the negative condition. Then using the Equine Facial Action Coding System (EquiFACS) and network analysis (NetFACS) we revealed distinct behaviours and facial expression profiles. In positive anticipation, the horses exhibited a greater range of behaviours, including shaking their heads from side to side, stepping back, sniffing, and pawing at the ground. Additionally, two distinct facial expression profiles were identified as specific to positive and negative anticipation. In positive anticipation, the horses displayed a higher neck, accompanied by a greater frequency of half-blinks and mouth movements. Conversely, in negative anticipation, the horses exhibited a medium neck, with ears backward accompanied by more flattened ears and expressed more nostril movements. The findings highlight the importance of these indicators in characterising horses' emotions and emphasise their significance for assessing equine welfare.
动物的福利与它们的情感体验密切相关，因此识别这些情感的可靠指标至关重要。本研究旨在识别经历不同情感效价的马匹的行为和面部动作，这些情感效价由对积极状况（前往牧场）或消极状况（独自前往新环境）的预期引发。二十匹马每天在起始箱中接受训练，等待接触这两种状况。在进行一周的积极训练或消极训练后，我们分析了马匹在起始箱中等待时的行为、皮质醇变化和面部动作。首先，我们证实这两种状况引发了不同的情感效价，积极状况下接近所需时间比消极状况短，以及消极状况下最高心率和皮质醇变化更高，这些都证明了这一点。然后，我们使用马面部动作编码系统（EquiFACS）和网络分析（NetFACS）揭示了不同的行为和面部表情特征。在积极预期中，马匹表现出更多样化的行为，包括左右摇头、后退、嗅闻和刨地。此外，识别出两种不同的面部表情特征分别特定于积极和消极预期。在积极预期中，马匹颈部抬高，半眨眼和嘴巴动作的频率更高。相反，在消极预期中，马匹颈部中等高度，耳朵向后，耳朵更扁平，鼻孔动作更多。这些发现突出了这些指标在表征马匹情感方面的重要性，并强调了它们对评估马福利的意义。
