Are olfactory stimuli able to induce emotional responses in a positive context in ewes?

Abstract

The perception of olfactory stimuli can influence animal emotions and behaviours, which are critical for survival and adaptation. This study explored the properties of three olfactory stimuli (orange essential oil, wolf faeces, and cadaverine) to induce emotion in sheep, in a non-stressful environment enriched with social and food resources. Contrary to expectations, wolf faeces, while repellent, did not trigger overt stress behaviours such as increased vocalisations or agitation. Similarly, orange essential oil did not elicit strong positive valence responses, suggesting that the positive experimental context may mask its effect. Interestingly, cadaverine, typically associated with body decomposition, has no impact on sheep behaviours except that is induced emetic responses in two individuals, indicating potential disgust. Overall, this research highlights the complex interplay between social, food, and environmental factors in shaping the emotional responses of sheep to olfactory stimuli, underscoring the importance of context and individual variability. These findings contribute to a better understanding of olfactory influences on animal welfare and behaviour.