Farm Animals

Pig Welfare and Aggression Management in Group Housing

Aggression at mixing is a critical welfare challenge in group-housed pigs, with evidence-based strategies now available to reduce harm.

Key Facts

Pigs establish dominance hierarchies through fighting, causing wounds and stress
Mixing unfamiliar pigs causes aggression peaks lasting 24-72 hours
Short-term straw provision during mixing reduces aggression by 30%
Gradual introduction protocols with barrier contact reduce escalation
Olfactory masking sprays are controversial but show some effect in trials

Welfare Considerations

Aggression at mixing is a significant welfare problem but is preventable with appropriate management. Investment in mixing protocols and enrichment pays welfare and production dividends.

What You Can Do

Advocate for group housing transition support and best practice guidance
Support research on aggression reduction strategies
Choose pork from farms using evidence-based mixing protocols