Modern commercial turkeys have been selectively bred for rapid breast muscle growth, creating serious welfare problems including leg disorders, cardiovascular disease, and inability to mate naturally.
Commercial turkey breeding represents an extreme case of welfare harm through selective breeding. The body proportions achieved through decades of selection for breast meat yield have created animals that struggle to walk comfortably, cannot reproduce naturally, and are prone to metabolic and cardiovascular disease. The welfare cost of each improvement in growth rate has been borne by the animals, not accounted for in selection indices. Heritage breeds demonstrate that turkeys can live without these imposed disabilities, though at higher production cost. Reform requires both breeding index revision to include welfare traits and consumer willingness to pay for slower-grown birds.