Pigs are among the most intelligent farmed animals and significant scientific research now documents their enrichment needs and the welfare benefits of environmental complexity.
Research into pig enrichment has advanced significantly over the past two decades. Pigs provided with rooting substrates including straw, compost, mushroom substrate, or peat show dramatically reduced tail biting, lower aggression, reduced cortisol, and improved immune function. The European Commission requires pigs to have access to manipulable materials but enforcement is inconsistent. Tail docking, practiced to reduce bite injuries in barren systems, is a symptom management approach that does not address the underlying welfare problem. Social complexity including mixing of unfamiliar pigs at weaning and during regrouping causes significant aggression and stress. Progress in pig welfare requires systemic change including space allowances, material provision, and reduced regrouping stress rather than individual interventions.