Pig behavioural science has produced some of the richest welfare indicators in animal agriculture. Understanding what pig behaviour reveals about their emotional states enables better welfare management.
Tail wagging in pigs indicates positive affective states; tail hanging or curled indicates neutral or negative states. Play solicitation postures are highly reliable welfare-positive indicators visible to trained observers. Escape motivation testing reveals the extent to which pigs are motivated to avoid their current environment. Cognitive bias tests where pigs trained on ambiguous cues show optimistic or pessimistic responses provide validated measures of emotional state. These indicators are increasingly incorporated into farm welfare assessment protocols.