The breed of broiler chicken chosen by producers has a profound effect on welfare outcomes. Slower-growing breeds consistently demonstrate better health and behaviour than fast-growing counterparts.
The primary driver of poor broiler welfare is extreme growth rate. Modern fast-growing breeds have been selectively bred for rapid muscle deposition to the point that their skeletal and cardiovascular systems cannot keep pace. The result is systemic health compromise: leg disorders, heart failure (ascites, sudden death syndrome), breast blisters from inability to stand comfortably, and immune suppression. Slower-growing breeds, by contrast, develop more gradually and show dramatically better welfare outcomes across all indicators. Transitioning the industry to slower-growing breeds is one of the most impactful single welfare improvements available.