Farm Animals

Pig Welfare and Welfare and Social Hierarchy Stress 2026

Social hierarchy stress in pigs causes welfare problems throughout the production cycle, with management strategies available to reduce its impact.

Key Facts

Pigs establish dominance hierarchies through fighting and biting, causing wounds and stress
Stress from social instability increases cortisol and suppresses immune function
Stable social groups show lower aggression, fewer injuries, and better welfare indicators
Introductions of unfamiliar pigs is the primary cause of social stress in commercial systems
Gradual introduction protocols and olfactory masking reduce aggression at mixing events

Welfare Considerations

Social hierarchy stress is a significant, manageable welfare problem. Management strategies that reduce mixing and support group stability prevent considerable suffering.

What You Can Do

Advocate for social group stability requirements in pig welfare certification
Support research on mixing stress reduction strategies
Choose pork from farms using evidence-based social management protocols