Selective breeding for production traits has inadvertently created or amplified genetic diseases in many livestock populations. Addressing genetic welfare problems requires coordinated breeding programs and industry-wide commitment.
The welfare consequences of genetic selection in livestock are often delayed: it takes generations before the full effects of selection for single traits become apparent. By the time double muscling creates a cattle breed that can barely give birth naturally, or leg weakness in fast-growing poultry becomes near-universal, the genetic change is embedded in commercial populations. Modern genomic tools offer an opportunity to correct course: by including welfare traits in selection indexes and using genomic markers for health-associated variants, breeders can simultaneously improve production and welfare. The challenge is persuading industry to value traits that don't directly increase output, which requires regulatory requirements or market incentives from welfare-conscious buyers.