Genetic selection in cattle has historically prioritised production at the expense of health and welfare traits, but modern selection indices increasingly incorporate welfare-relevant health data.
Generations of selection for maximum production have inadvertently created cattle with higher susceptibility to metabolic disease, mastitis, and lameness. High-yielding cows experience the chronic welfare cost of metabolic stress during early lactation. Modern breeding indices that include health traits can reverse this trend, but the changes require decades of consistent selection to have population-level effect.