Measuring positive emotional states in pigs advances beyond absence-of-harm welfare assessment to actively quantify and promote happiness, play, and positive anticipation in farm settings.
Positive welfare science recognizes that freedom from suffering is a necessary but insufficient welfare standard. A pig may be free from injury and disease while existing in a state of chronic boredom and psychological emptiness that does not constitute a life worth living. Measuring and promoting positive emotional states — play, exploration, anticipation of rewards, and social bonding — defines a higher standard that progressive welfare systems are beginning to incorporate. The Five Domains model of animal welfare explicitly includes mental state as a welfare domain, requiring positive mental experience not just absence of suffering. Farms that actively promote positive welfare through enrichment, appropriate social grouping, and positive human-animal relationships produce animals whose lives contain genuine positive experiences.