Pig Aggression Management and Welfare

Aggression in pigs causes significant welfare harm through injury, stress, and disruption of normal feeding and resting behaviour, with prevention strategies available through management and enrichment.

Key Facts

Mixing unfamiliar pigs triggers aggression as hierarchy is established over 24-48 hours
Injuries from fighting include skin lesions, ear bites, and in severe cases, fatalities
Stocking density above welfare thresholds significantly increases aggression rates
Enrichment that engages rooting and foraging motivation reduces redirected aggression
Providing multiple feeding and resting areas reduces resource competition-driven aggression

Welfare Considerations

Pig aggression welfare harm is both acute (injuries during hierarchy establishment after mixing) and chronic (ongoing resource competition in overcrowded conditions). The welfare management of aggression requires addressing root causes: mixing frequency can be reduced by stable group management; resource competition can be reduced by adequate trough and resting space; redirected aggression can be reduced by enrichment that satisfies rooting and foraging drives. Anti-aggression sprays and management interventions treat symptoms — structural management changes address causes.

What You Can Do

Support certification schemes with stable group management requirements
Advocate for stocking density limits based on aggression outcome evidence
Choose pork from farms with documented social management welfare protocols
Support research into genetic selection for reduced aggression in pigs
Engage with pig industry welfare organisations on aggression management best practice