Welfare science of extreme litter size selection in commercial pig breeding, examining the welfare costs of hyperprolificity for sows and piglets, and the case for more moderate selection targets.
The drive toward ever-larger litters in commercial pig breeding represents a case where production goals have been pursued beyond the point where animal welfare can be maintained. When sow lines are selected to produce 17+ piglets per litter, the welfare costs are distributed across multiple animals: the sow faces extreme metabolic demands; born piglets compete for inadequate teat numbers; light-born individuals face survival challenges. The industry response of using nurse sow systems compounds the welfare cost by creating additional social disruptions. A more welfare-compatible breeding philosophy would balance litter size against piglet birth weight, viability, and sow health — pursuing breeding targets that maintain welfare integrity alongside productivity. Consumer and regulatory pressure toward welfare-conscious breeding can reshape industry incentives.