Play in pigs - including locomotor play, social play, and object play - is a reliable positive welfare indicator that enrichment and good management conditions promote.
The observation of play in pigs is increasingly used as an objective measure of positive welfare states. Play requires surplus energy and a sense of safety - animals under stress, in pain, or resource-limited do not play. When pigs in enriched systems are seen to bound, twist, and engage in social rough-and-tumble, this is an observable indicator of positive internal states. The integration of positive welfare indicators like play into farm assessment transforms welfare monitoring from a floor of minimum acceptability toward an aspiration for positive experience. Farms that achieve regular play behavior across their pig populations are demonstrating something meaningful about the quality of those animals' lives.