Weaner Pig Management: Welfare After Nursery

The weaner stage — roughly 10 to 25 kg liveweight — bridges the nursery and growing phases in commercial pig production and carries distinct welfare risks around mixing, space, and disease challenge.

Key Facts

Weaners are moved from nursery facilities to grower housing at approximately 10 weeks and 25 kg in commercial systems
Mixing of groups from different nursery pens at this stage causes fresh fighting as social hierarchies re-establish
Respiratory disease is common in weaners — enzootic pneumonia (Mycoplasma hyopneumoniae) is endemic in many herds
Space allowances are often at or near legal minimums, which research shows are insufficient for positive welfare outcomes
Environmental enrichment — manipulable substrates like straw, chains, or wood — significantly reduces tail biting in weaners
Temperature management remains important: weaners in draughty or cold environments show increased huddling and reduced activity
Lameness originating in weaner pens often goes undetected, persisting into the growing stage with cumulative welfare costs

Welfare Considerations

Weaner pigs face a convergence of stressors: a new social environment, unfamiliar housing, increased pathogen exposure, and greater competition for resources. The period between 10 and 16 weeks is particularly associated with tail biting outbreaks, which cause serious wounds and infection if not managed quickly. Respiratory disease during this period suppresses growth and causes significant discomfort — coughing, fever, and reduced activity are common. Where stocking density is high and enrichment absent, weaner pens become environments of chronic frustration and low-grade suffering. Research consistently demonstrates that lower stocking densities, routine enrichment provision, and stable social groups substantially improve welfare outcomes for this vulnerable age group.

What You Can Do

Support pork producers who maintain stable social groups and avoid unnecessary mixing at weaner stage
Choose pork certified to higher welfare standards that require enrichment and lower stocking densities
Advocate for legislation updating minimum space allowances based on current welfare science
Report signs of tail biting or untreated illness in visible pig pens to appropriate animal welfare authorities
Reduce pork consumption or switch to plant-based alternatives to reduce demand for intensive weaner systems
Support farm animal welfare research into enrichment strategies that work at commercial scale