Modern pig welfare assessment increasingly measures positive welfare states — play behaviour, exploration, and indicators of positive affective states — alongside the traditional absence of pain and disease.
Pigs in barren environments without enrichment show dramatically less play behaviour than those in enriched conditions — indicating reduced positive welfare state frequency. Play behaviour decreases when pigs are ill, in pain, or under chronic stress, making it a sensitive indicator of welfare change. Pigs provided with straw, novel objects, and social stability show more exploration and play than those in barren, overcrowded pens. Positive welfare assessment tools developed by EURCAW-Pigs and others enable farmers to track welfare improvement beyond simply reducing disease and injury.