The intensive selection of livestock for production traits has narrowed genetic diversity, increasing disease susceptibility and welfare vulnerability. Maintaining diverse gene pools is important for long-term animal welfare.
Genetic uniformity in livestock is a hidden welfare risk. When entire national herds share similar genetic backgrounds, a single pathogen variant to which that genotype is susceptible can cause welfare catastrophe at scale — as seen in disease outbreaks that devastated genetically uniform populations. More immediately, the traits selected for in modern livestock — extreme milk yield in dairy cows, rapid muscle growth in broilers and turkeys — are often in direct tension with health and welfare. Maintaining diverse breeds, including those selected for health, longevity, and adaptability rather than peak production, provides a welfare buffer and evolutionary insurance. Supporting heritage breed conservation is both a welfare and a food security intervention.