The stress of early weaning in commercial pigs creates a cascade of gut health problems that cause significant welfare harm, with post-weaning diarrhea and gut microbiome disruption affecting the majority of weaned piglets.
Post-weaning diarrhea causes acute welfare harm — dehydration, abdominal pain, and weakness — that affects a large fraction of commercial pigs in the days following weaning. The welfare cost is a predictable consequence of weaning at an age before gut maturity is complete. Management responses including dietary optimization and gradual weaning transitions reduce but do not eliminate the problem. The underlying solution — later weaning that allows gut maturation — is the most welfare-consistent approach.