Modern fast-growing broiler breeds grow so rapidly that many cannot support their own body weight, experiencing chronic pain, lameness, and cardiovascular disease that affect billions of birds annually.
The welfare problems of fast-growing broiler breeds represent a systemic breeding welfare failure — chickens have been bred to grow so rapidly that their skeletal, cardiovascular, and immune systems cannot keep pace. The result is birds that spend much of their short lives in pain from leg disorders, unable to walk normally, unable to engage in natural behaviours, and suffering from chronic systemic disease. This is not an inevitable consequence of raising chickens for food; it is a consequence of prioritising growth rate above all other traits. Slower-growing breeds produce birds with dramatically better welfare outcomes and are increasingly available through higher-welfare certification schemes.