Aggression Management in Pig Groups

Aggression is a major welfare problem in group-housed pigs, causing injury, stress, and reduced productivity, with management interventions able to dramatically reduce its incidence.

Key Facts

Pigs establish dominance hierarchies through fighting, with most aggression occurring at mixing and competition points
Tail biting affects up to 30% of EU pigs despite being linked to correctable management factors
Reducing stocking density by 10% can reduce aggression by up to 30%
Visual barriers including partitions and hiding boards dramatically reduce injury during mixing events

Welfare Considerations

Pig aggression welfare is primarily a management problem with management solutions. Mixing unfamiliar pigs, competition for limited resources, and environmental barrenness are the main aggression drivers — all modifiable. Stable groups established before mixing age, adequate space, multiple feeding points, visual barriers during mixing, and rooting enrichment all reduce aggression. The tail biting problem is a downstream consequence of housing conditions that frustrate natural behaviour rather than an inevitable feature of pig production. Systems designed for welfare rather than minimum compliance can dramatically reduce injury prevalence.

What You Can Do

Support welfare standards that require adequate space and enrichment to reduce pig aggression
Advocate for maximum stocking density limits based on welfare evidence
Choose pork from farms with documented low injury and aggression rates
Support farmers implementing management changes that reduce aggression without compromising economic viability