Play behaviour in pigs is a positive welfare indicator demonstrating that animals have energy and motivation beyond mere survival. Understanding and facilitating pig play is an important part of providing genuinely good welfare, not just absence of suffering.
The Five Domains framework for animal welfare includes positive mental states as a welfare domain alongside the traditional four domains of nutrition, environment, health, and behaviour. Play is one of the clearest behavioural indicators of positive mental states in pigs. Its presence signals sufficient physical reserves, psychological security, and motivational capacity that extend beyond meeting basic needs. Conversely, its absence signals welfare compromise — overcrowded, sick, or chronically stressed pigs do not play. Enrichment that facilitates play, including rooting substrates, novel objects, and sufficient space for locomotory play, improves welfare significantly even when other welfare indicators are adequate. Assessing play frequency and quality should be part of routine farm welfare monitoring.