The genetic selection of broiler chickens for extreme growth rates has created animals with compromised health and welfare — and a growing body of evidence supports the welfare and economic case for slower-growing alternatives.
The welfare harm built into fast-growing broiler genetics is fundamental rather than incidental — it is the direct consequence of selecting for one trait (growth rate) without welfare constraints. Animals bred to grow at the rate of fast-growing broilers develop leg weakness, cardiovascular failure, and ascites at predictably high rates because their physiological systems cannot keep pace with their growth rate. This is not a farm management failure that better husbandry can fully correct — it is a genetic design problem that requires genetic solutions. Slower-growing breeds with better welfare outcomes exist and are commercially viable, demonstrating that the choice to use fast-growing breeds is a commercial decision with welfare costs rather than an unavoidable necessity.