Broiler Breast Muscle Myopathies: A Growing Welfare Crisis

Intensive selection for rapid breast muscle growth in broiler chickens has created new muscle diseases affecting welfare and meat quality. Understanding these conditions drives breed reform and welfare improvement efforts.

Key Facts

Wooden breast, white striping, and spaghetti meat are muscle myopathies increasingly prevalent in fast-growing broiler breeds
These conditions result from the extreme breast muscle growth rate outpacing blood supply capacity
Affected muscles show inflammation, fibrosis, degeneration, and accumulation of fat and connective tissue
Prevalence of white striping exceeds 50% in many commercial fast-growing broiler flocks
Myopathy-affected birds show reduced mobility and difficulty accessing feed and water
Slower-growing breeds show dramatically lower rates of breast muscle myopathies
The Better Chicken Commitment requires transition to slower-growing breeds that largely avoid these conditions

Welfare Considerations

Breast muscle myopathies represent a welfare consequence of extreme selective breeding — chickens have been engineered to grow so fast their bodies cannot maintain healthy muscle tissue. Affected birds experience localised pain and inflammation from necrotic muscle tissue. Mobility impairment from breast weight and leg weakness compounds the welfare harm. These conditions are intrinsic to fast-growing genetics and cannot be eliminated through housing or management improvements alone — only breed change resolves the fundamental problem.

What You Can Do

Support the Better Chicken Commitment by choosing retailers and restaurants that have signed it
Ask food companies about their progress toward eliminating fast-growing broiler breeds from their supply chains
Support research into slower-growing breed performance under various housing conditions
Reduce chicken consumption or choose certified products from producers using appropriate breeds
Contact your elected representatives about minimum broiler welfare standards including breed requirements