Pig Weaning Stress: Age, Nutrition, and Environment

Commercial weaning of piglets at 3-4 weeks causes acute stress from social disruption, dietary change, and unfamiliar environment; management strategies significantly mitigate these welfare costs.

Key Facts

Wild pigs wean naturally at 8-17 weeks compared to commercial weaning at 21-28 days
Weaning is associated with elevated cortisol, vocalisation, and increased aggression
Post-weaning diarrhoea is the leading cause of mortality in commercially weaned piglets
Transition feeding protocols and mixed bedding environments reduce weaning stress indicators

Welfare Considerations

The weaning stress complex in commercial pig production involves simultaneous disruption to social bonds, nutrition, housing, and group composition — a perfect storm of welfare insults that compromises both piglet welfare and immune function. Later weaning at 28 days or more reduces stress indicators and disease incidence compared to 21-day weaning. Management interventions including familiar bedding in the weaning pen, gradual dietary transition, and small stable group composition buffer but do not eliminate weaning stress.

What You Can Do

Support producers weaning at 28 days or later rather than 21 days
Advocate for minimum weaning age legislation consistent with welfare evidence
Choose pork from producers with documented weaning management protocols