The genetics of broiler chickens are central to their welfare outcomes. The shift from fast-growing to slower-growing breeds is one of the most impactful structural changes available to improve welfare for billions of chickens globally.
Broiler genetics is arguably the single most important structural determinant of chicken welfare at scale. Fast-growing breeds produce birds that outgrow their cardiovascular and skeletal systems, resulting in a population-wide welfare burden from painful locomotion problems, heart failure, and chronic skin lesions. The prevalence of these conditions in fast-growing commercial flocks is not an accident or management failure — it is the predictable outcome of extreme selection for growth rate. Slower-growing breeds, by contrast, reach slaughter weight with significantly lower rates of these conditions, a better ability to move and engage in natural behaviours, and lower mortality. The trade-off is higher production costs and longer time to slaughter weight. The welfare case for transition to slower-growing breeds is clear and the economics, while challenging, are manageable through modest price premiums that consumer surveys suggest significant numbers of people are willing to pay for certified higher-welfare chicken.