Providing sufficient rooting substrate is the most evidence-based intervention for preventing tail biting in pigs, with research clearly demonstrating effectiveness over minimal-enrichment approaches.
Enrichment substrate evidence is unambiguous - straw works for reducing tail biting and most alternatives do not come close. The welfare challenge is that effective enrichment (straw) is incompatible with the slurry-based housing systems common in UK pig production, creating a structural barrier to welfare improvement that requires investment in alternative housing design. Farmers in straw-based systems have lower tail biting rates and less need for tail docking. The industry transition from slurry to straw-compatible housing requires capital investment and policy support - but it represents a genuine welfare improvement path rather than compliance-gaming with inadequate enrichment items. Welfare policy should align with substrate evidence rather than accepting token enrichment.