Research has systematically compared different enrichment materials for pigs, identifying what works best for meeting behavioral needs and reducing problem behaviors.
Pig enrichment material research provides one of the clearest evidence bases in applied animal welfare science for matching provision to behavioral need. The hierarchy of enrichment effectiveness consistently places organic, destructible substrate materials at the top and fixed non-destructible objects at the bottom. A chain hanging in a pen satisfies EU minimum requirements but provides essentially no behavioral benefit to a species that evolved for complex substrate manipulation. Straw, compost, peat, and silage — materials that pigs can root through, bite, and destroy — satisfy the rooting drive by providing the sensory feedback and behavioral completion that fulfills the underlying motivational state. This evidence base should inform regulatory minimum standards that move beyond the chain toward genuinely effective enrichment provision.