Farm Animals

Pig Social Hierarchy: Management and Welfare

Pigs establish and maintain complex social hierarchies that determine resource access, with management of mixing and grouping directly determining whether hierarchy establishment causes significant welfare harm.

Key Facts

Mixing unfamiliar pigs causes fighting for up to 72 hours as hierarchies are established
Blood injuries from fighting are common when mixing unfamiliar groups
Stable social groups show significantly lower stress indicators than repeatedly regrouped animals
Electronic identification enables feeding without social competition through individual feed stations
Farmers can minimize mixing stress through timing, space provision, and distraction during introduction

Welfare Considerations

Pig social hierarchies are natural but the intensity of fighting when unfamiliar groups are mixed creates acute welfare harm from bite wounds, social stress, and exhaustion. Production systems that require frequent regrouping — for weight sorting, health treatment, or sale — impose repeated hierarchy establishment stress. Stable group management significantly reduces this welfare burden.

What You Can Do

Support certification schemes requiring minimal regrouping of pigs through production
Advocate for stocking densities that allow pigs to avoid dominant individuals after mixing
Choose pork from farms with documented low mixing frequency practices
Donate to organizations working on pig social welfare research and management
Engage with food businesses about their pig regrouping requirements in supply chain standards