Selective breeding has driven extraordinary productivity gains in farm animals over the past century, but in many species has simultaneously created genetic welfare problems that now represent some of the most severe and widespread welfare challenges in animal agriculture.
Selective breeding for production performance has created welfare crises embedded at the genetic level — problems that cannot be solved through management improvements alone because the welfare harm is structural to the animal's biology. A broiler chicken's leg disorders are not caused by poor husbandry but by a growth rate its skeleton cannot support. A Bulldog's breathing difficulties are not caused by inadequate veterinary care but by skull anatomy selected for human aesthetic preference. These are welfare harms deliberately created through human selection, persisting because the economic and cultural incentives to maintain them outweigh the welfare costs imposed on the animals involved. Addressing them requires engaging with genetics, breed standards, and the economics of the production systems that perpetuate harmful trait selection.