Evidence-based review of enrichment materials for pigs in commercial production and which types most effectively reduce harmful behaviors and improve welfare.
Pig enrichment science has evolved significantly, moving from the assumption that any object constitutes enrichment to a more nuanced understanding of which materials actually satisfy pig behavioral drives. The distinction is critical: a chain hanging in a pen provides some manipulation opportunity, but straw that pigs can root through, chew, and nest in engages far more of the behavioral repertoire with far greater efficacy. Regulatory minimum requirements for enrichment have set a low baseline that allows farms to comply while providing poor enrichment quality. Consumer-facing welfare standards that specify straw or equivalent high-quality materials, and the quantities needed to be effective, represent a meaningful welfare improvement over simple enrichment-present/absent requirements. The science is clear; the implementation gap is what needs closing.