Play behaviour in pigs is a reliable indicator of positive welfare states, and enrichment conditions that promote play are associated with multiple welfare benefits.
Play as a welfare indicator is significant because it is a positive state marker: pigs do not play when stressed, ill, or fearful. Play bouts require surplus energy and a sense of safety — both indicators of good welfare. Enrichment that increases play frequency is therefore demonstrably improving welfare beyond the absence of suffering. The relationship between play and reduced redirected behaviour suggests that play satisfaction reduces motivation for harmful behaviours — a welfare benefit with production co-benefits.