Play behaviour in pigs — including running, jumping, social play fighting and object manipulation — is a positive welfare indicator. Environments that prevent play reflect impoverished conditions and reduced pig wellbeing.
The presence or absence of pig play behaviour is a direct welfare window. Pigs on bare concrete in barren environments show almost no spontaneous play — the welfare deficit is measurable. Pigs with access to straw, objects and varied environments not only play more but also show lower stress hormone levels, fewer aggressive interactions and better immune function. The Five Domains framework now explicitly includes positive emotional states — and play is one of the clearest indicators of animals experiencing positive affect. Enrichment programmes that increase play do not reduce productivity and significantly improve welfare outcomes.