What pig play behavior tells us about welfare state, how it can be used as a welfare assessment tool, and what conditions support play.
Play is a welfare indicator because it is resource-demanding behavior performed only when basic needs are met and the animal feels safe. Pigs in pain, fearful environments, or poor health do not play. The presence of active play therefore indicates positive welfare states rather than just absence of negative states, making it a valuable positive welfare indicator. Monitoring play behavior in commercial pig systems provides real-time welfare assessment that complements physical health measures. Enrichment that supports play also addresses other welfare needs including foraging and social interaction.