Modern broiler chickens have been selectively bred to grow so fast that their bodies struggle to support their own weight, causing widespread suffering.
Fast-growing broiler genetics represent one of the most severe systemic welfare problems in modern agriculture. Chickens bred for extreme growth rates suffer from bodies that fundamentally cannot support their own biology. The heart and lungs cannot keep pace with the rapidly growing mass of breast muscle, causing cardiac arrest and fluid accumulation (ascites) in millions of birds annually. Skeletal systems buckle under extreme weight, causing painful lameness — birds that cannot walk adequately cannot access food and water. The breast muscles grow so large that birds cannot perform natural behaviors like dustbathing or wing-spreading. These problems are not accidents of farming conditions — they are built into the animal's genome. The Better Chicken Commitment advocates for transition to slower-growing breeds that show dramatically better welfare outcomes.