Selection for large litter sizes has created welfare problems as neonatal survival decreases and piglet birth weight falls with larger litters.
The race for ever-larger litter sizes has created a welfare crisis at the neonatal stage. Piglets from oversized litters are lighter, compete more intensely for colostrum, and die at higher rates. The suffering of neonatal piglets struggling to access nutrition in overcrowded litters is a direct consequence of genetic selection priorities that ignored welfare. Rebalancing selection to include birth weight, survival, and teat access is essential.