Commercial pig farming weans piglets at 21 days or younger, far below the natural weaning age of 12-17 weeks. The welfare implications are significant for both sows and piglets.
Commercial pig weaning at 21 days is a significant welfare compromise driven by production efficiency rather than animal welfare. At this age, piglets have incompletely developed immune systems, incompletely formed digestive tracts, and strong behavioral drives for suckling that cannot be met once separated. The belly-nosing behavior common in early-weaned piglets — where they suckle on each other's flanks and bellies — is a welfare indicator reflecting unsatisfied oral behavioral needs. Extending weaning age even modestly to 28 days shows measurable welfare improvements and is the EU minimum standard. More substantial welfare improvement would come from weaning at 5-6 weeks or beyond, but this requires housing system changes that impose production costs. The welfare case for extended weaning is clear; the barrier is primarily economic.