Genetic selection for large litter sizes in pigs has created significant welfare problems for piglets that cannot all be sustained by sows.
Hyperprolific pig breeding welfare represents a systemic problem created by selecting for a single production trait without considering the cascade of welfare consequences. Large litters produce piglets that cannot all be adequately nourished by the sow, creating competition for teats, differential access to colostrum, and high neonatal mortality for the smallest individuals. The welfare of dying or failing piglets — weak, cold, unable to compete for teat access — represents genuine suffering that is a predictable consequence of extreme selection pressure. Genetic selection for moderate, sustainable litter sizes alongside good maternal ability represents the welfare-positive breeding direction, though it conflicts with the production economics that have driven hyperprolific selection.