Farm Animal Welfare

Pig Social Hierarchy and Stress Reduction

Understanding and managing pig social hierarchies reduces aggression and improves welfare outcomes in group-housed systems.

Key Facts

Pigs establish dominance hierarchies through fighting when mixed
Regrouping stress peaks within 24-48 hours of introduction
Stable groups show lower cortisol and fewer injuries
Space allowance strongly influences hierarchy formation intensity
Familiar odors can reduce mixing aggression significantly

Welfare Considerations

Social stress from regrouping is a major welfare challenge. Strategies like mixing at night, providing visual barriers, and using familiar bedding reduce fighting duration and injury rates.

What You Can Do

Minimise regrouping frequency in pig management
Provide adequate space and refuges for subordinate animals
Use olfactory masking when introducing unfamiliar pigs