Welfare science has established a robust evidence base for pig enrichment, identifying which substrates and materials most effectively meet behavioural needs.
Pig enrichment science has progressed to the point where specific recommendations can be made based on robust evidence. The behaviour-based hierarchy of enrichment effectiveness places manipulable substrates at the top: straw, compost, and similar materials address the rooting drive that is among the highest-motivated behaviours in pigs. Hanging objects — chains, rubber toys, wooden blocks — address some exploratory needs but cannot fulfil the rooting motivation that requires substrate to push nose through. This explains why studies show straw consistently outperforms point-object enrichment on tail biting and welfare indicator outcomes. The practical challenge for producers is that straw creates manure management difficulties in slatted floor systems — solutions including partial substrate provision in separate exploration areas are being developed. Consumer-facing welfare standards should specify substrate quality, not just the presence of any enrichment.