Broiler Chicken Growth Rate and Welfare

Modern broiler chickens grow so fast that their cardiovascular and skeletal systems cannot keep pace, causing endemic welfare problems.

Key Facts

Commercial broilers reach market weight in 42 days — three times faster than birds in 1950
Ascites (fluid accumulation in body cavity due to cardiovascular failure) affects 1 to 5% of commercial broilers
Lameness from skeletal problems affects 30 to 40% of broilers at market age
Slower-growing breeds reach market weight in 56 to 70 days and show dramatically lower leg disorder rates
The EU Broiler Directive sets minimum standards but does not address growth rate as a welfare variable

Welfare Considerations

Growth rate is the single most impactful welfare variable in broiler production. Breeds that grow faster than their cardiovascular and skeletal systems can support create endemic pain and disability. Transitioning to slower-growing breeds represents the most significant single welfare improvement available in commercial chicken farming.

What You Can Do

Choose chicken products from slow-growth certified programs such as Better Chicken Commitment signatories
Advocate for retailers to adopt the Better Chicken Commitment requiring slower-growing breeds
Support regulatory frameworks that cap broiler growth rates as a welfare standard