Pig Weaner Welfare and Post-Weaning Stress Syndrome

Weaning piglets at 21 days causes significant welfare impacts including immune suppression, post-weaning diarrhoea, and social disruption that can be mitigated by later weaning and better management.

Key Facts

EU legislation requires weaning no earlier than 28 days except in emergency
UK commercial practice commonly weans at 21-28 days for production efficiency
Post-weaning diarrhoea is the leading cause of piglet mortality in weaner systems
Weaning involves simultaneous loss of mother, familiar environment, siblings, and milk diet
Social mixing of litters at weaning creates fighting stress in addition to dietary transition

Welfare Considerations

Weaning is the most welfare-challenging period in the commercial pig lifecycle. Piglets face the abrupt removal of maternal warmth and milk, transfer to an unfamiliar environment, introduction to solid food, and mixing with unfamiliar pigs simultaneously. The combined stressors cause immune suppression, making weaners highly susceptible to bacterial diarrhoea. Post-weaning diarrhoea causes pain, dehydration, and significant mortality. Later weaning, maintaining sibling groups, and good transition feeding significantly improve welfare outcomes.

What You Can Do

Support minimum 28-day weaning age requirements in farm welfare standards
Advocate for management practices maintaining sibling groups through weaning
Choose pork from certified higher welfare systems with later weaning standards
Support research into weaning stress mitigation through nutrition and housing design
Engage with farm assurance bodies about post-weaning mortality as a welfare outcome indicator