Play behaviour in pigs is a validated positive welfare indicator, and its frequency in commercial herds provides a measurable signal of welfare quality that correlates with other welfare outcomes including lower stress and aggression rates.
Play in pigs is not frivolous behaviour but a genuine welfare signal that reflects the emotional state of the animal. Pigs that play are pigs that have sufficient energy, adequate nutrition, social stability, and environmental richness to express this positive state. Play declines when any of these conditions are compromised, making its absence an early warning sign of welfare problems before more obvious negative indicators appear. For farm welfare assessment, counting play bouts during an observation period provides a rapid, non-invasive positive welfare measure that complements the negative indicators of injuries, lameness, and stereotypies. Promoting play-enabling conditions benefits both animal welfare and farm productivity through reduced stress and aggression.