Research on environmental enrichment for pigs has produced a robust evidence base for what works, what does not, and why enrichment is a welfare necessity rather than a luxury.
The research base on pig enrichment is among the strongest in any livestock species. Straw and other manipulable materials dramatically reduce the harmful redirected behaviours that develop when rooting motivation is unmet. Simple enrichment objects like chains are less effective because they lack the qualities that sustain pig interest — novelty, destructibility, and natural properties. This research has direct welfare implications: effective enrichment reduces injury from tail biting, promotes play and positive affect, and provides objective evidence that enriched pigs are better-off. The challenge is translating this evidence into consistent management practice on commercial farms.