Research into enrichment materials for pigs has identified which types most effectively meet behavioral needs, informing practical standards for commercial pig farming.
Pig enrichment science has produced clear evidence about what works. Substrate enrichment — materials that pigs can root through, manipulate, and forage in — meets behavioral needs far more effectively than hanging objects. Straw is the gold standard: it satisfies rooting, manipulation, and thermal comfort needs simultaneously. Compost, peat, and mushroom substrate provide similar benefits. Hanging chains, rubber toys, and wood blocks are widely used to comply with the letter of EU regulations but satisfy behavioral needs far less effectively. The gap between legal compliance and actual welfare is substantial. Countries and certifications that require substrate enrichment (Sweden, RSPCA Assured) rather than merely manipulable materials produce demonstrably better welfare outcomes.