Tail biting in pigs is a major welfare problem in commercial farming that indicates environmental deprivation and causes significant pain and injury.
Tail biting is simultaneously a welfare problem in itself and an indicator of deeper welfare failures in the farming system. When pigs bite each other's tails, the victims suffer open, infected wounds that cause significant pain and can progress to spinal abscesses and death. However, the act of tail biting is driven by the biting pig's own unmet behavioral needs - in barren environments, investigatory behavior directed at pen mates' tails becomes a substitute for normal rooting and foraging. The most welfare-positive response addresses root causes: providing enrichment, reducing stocking density, improving air quality, and ensuring adequate nutrition. Routine tail docking without enrichment provision reduces biting rates but represents a trade of one welfare compromise for another without fixing the underlying environmental deficiency.