Selective breeding has created significant welfare problems in livestock. Incorporating health and welfare traits into breeding programs is among the highest-leverage welfare interventions available.
Selective breeding is the most powerful long-term lever for improving or worsening livestock welfare. Decades of selection for production traits — milk yield, growth rate, egg production — without balancing selection for health and welfare has created populations with endemic health problems. Modern genomic selection tools allow simultaneous improvement of multiple traits, making it technically feasible to improve welfare traits without sacrificing production. The Nordic cattle breeding programs demonstrate this at scale: incorporating mastitis resistance, reproductive efficiency, and longevity alongside milk yield has produced cows with better welfare outcomes and comparable production to breeds selected for yield alone. Expanding this model to other species and traits is technically possible but requires political and commercial will.