Selective breeding decisions in farm animals have profound welfare implications, with some modern breed characteristics causing widespread chronic suffering.
The genetics of farm animals are perhaps the single most powerful determinant of their lifetime welfare potential. Breeding programs that relentlessly select for production traits - growth rate, milk yield, litter size - without corresponding selection for the biological systems that support those traits produce animals whose bodies are overwhelmed by the performance demands placed on them. High-producing dairy cows are metabolically pushed to their biological limits; fast-growing broilers develop bodies that cannot support their own weight. Including welfare indicator traits - longevity, lameness rates, metabolic disease incidence, body condition stability - in breeding objectives alongside production traits is technically feasible and has been demonstrated to improve welfare outcomes. The challenge is aligning economic incentives with welfare-positive selection objectives.