Research on pig enrichment has identified which objects and materials most effectively meet behavioral needs and reduce boredom and aggression in intensive housing systems.
Pig enrichment science has reached sufficient maturity to offer clear, evidence-based recommendations for welfare improvement. The finding that chains and balls — the most commonly provided enrichment items — are dramatically inferior to substrate-based enrichment represents an important gap between regulatory compliance and genuine welfare benefit. Straw addresses the rooting drive directly and provides a substrate for nesting behavior critical for sows before farrowing. For systems that cannot use deep bedding — including many slatted-floor intensive systems — daily provision of compostable materials that can be rooted and manipulated offers a partial substitute. Rotating novel materials to prevent habituation maintains behavioral engagement. The evidence base now supports specific recommendations: enrichment regulations should specify manipulable, investigable, and ideally edible materials rather than simply requiring any enrichment object.