How selective breeding in pigs has created welfare problems through extreme productivity traits and how welfare-oriented breeding programs are developing better solutions.
Pig genetic selection has delivered extraordinary productivity improvements but created structural welfare problems embedded in the genetics of modern commercial lines. Hyperprolific sows are selected for litter size beyond their nursing capacity, creating inevitable competition, injury, and death among neonates. Piglets from large litters are lighter, weaker, and more vulnerable — welfare compromises baked in before birth. Addressing these problems requires integration of welfare traits into breeding indices alongside productivity — a shift that is slowly occurring as welfare science and commercial interest align around the health and survival costs of extreme productivity genetics.