Pig Welfare in the Nursery Phase: Post-Weaning Stress Management (2026)

The nursery phase (weaning to approximately 10 weeks) is the most welfare-challenging period in commercial pig production, with mixing stress, dietary transition, and disease pressure combining to cause significant suffering.

Key Facts

Commercial pigs are weaned at 21-28 days in the EU, far earlier than the natural weaning age of 3-4 months
Post-weaning diarrhoea (PWD) caused by pathogenic E. coli is the leading cause of piglet mortality in nursery units
Mixing of litters at weaning causes fighting as dominance hierarchies are re-established
In-feed zinc oxide (banned in EU from 2022) was widely used to control PWD — alternatives are under intensive development

Welfare Considerations

Weaned piglets experience simultaneous loss of maternal contact, social disruption from mixing, diet change from milk to dry feed, and new pathogen exposure. Cortisol remains elevated for up to two weeks after weaning. Post-weaning diarrhoea causes fluid loss, abdominal pain, and death in severe cases. Fighting injuries from mixing include ear tip loss, tail injuries, and flank biting. Nursery conditions with high stocking density, poor ventilation, and inadequate enrichment compound stress and disease burden.

What You Can Do

Advocate for later weaning ages that allow piglet gut and immune development to proceed further
Support research into non-antibiotic interventions for post-weaning diarrhoea control
Encourage enrichment provision in nursery units to redirect aggression and reduce fighting injuries
Choose pork from welfare-certified systems with higher weaning age standards where available