Ear and tail postures as indicators of emotional valence in sheep

摘要: Abstract To date, most studies on animal emotions have focused the assessment of negative emotional states, and there is a lack approaches to characterising positive states. The aim this investigation was measure differences in ear tail postures sheep exposed situations likely induce states negative, intermediate valence. Nineteen female were observed emotion-eliciting two experiments. In home-pen experiment, during separation from group members (negative situation), rumination (intermediate), while feeding fresh hay (positive situation). fodder individual conditioned anticipate delivery standard feed. Once familiar with experimental condition, they offered either feed (control treatment), unpalatable wooden pellets or energetically enriched mixed preferred items treatment). Ear recorded final 6 min preceding (anticipation phase) for (feeding phase). Data analysed using linear mixed-effect models. separated showed high number ear-posture changes proportion forward ears compared feeding, which mainly passive. total generally anticipation phases, slightly lower pellets, clearly reduced A higher passive occurred when pellets. asymmetric axial influenced by sequence testing different treatments, first exposure sheep's tails being raised only members. both experiments, frequent associated inducing Unfamiliarity reactions towards more appraisal. appears occur specific situations, not useful distinguishing Apart need further validation, observations seem be promising approach assessing sheep.