Research into optimal enrichment substrates for pigs demonstrates that rooting materials providing resistance and novelty most effectively satisfy natural behaviour and reduce welfare problems.
Enrichment research demonstrates that the welfare benefits of pig enrichment depend on the specific materials provided. Pigs have an intrinsic motivation to root through materials with resistance — a motivation that cannot be satisfied by hanging objects or smooth surfaces. Straw and other rootable materials satisfy this motivation, reducing the redirected aggression and tail biting that cause significant welfare harm in barren housing. The research evidence is sufficiently strong to inform regulatory standards, but implementation requires commitment from producers who must manage the practical challenges of straw-based housing. Systems that achieve equivalent welfare through alternative rootable substrates demonstrate that the principle of motivation satisfaction matters more than the specific material.