Broiler Feed Conversion and Welfare Consequences

The intense genetic selection of modern broiler chickens for rapid feed conversion has created welfare problems including cardiovascular disease, skeletal disorders and organ failure in young birds.

Key Facts

Modern Ross 308 and Cobb 500 broilers reach market weight in 35-42 days, down from 84 days in 1957
Heart and lung problems including ascites and sudden death syndrome affect 1-4% of modern broilers
Skeletal disorders from rapid growth cause lameness and walking difficulty in 25-30% of commercial birds
Fast-growing breeds spend significantly more time lying down and less time engaging in natural behaviours
Slower-growing breeds (56+ days to market) show dramatically better leg and cardiovascular health
The Better Chicken Commitment requires slower-growing breeds as its most significant welfare requirement

Welfare Considerations

The welfare consequences of extreme selection for feed conversion efficiency in broiler chickens are profound and widespread. These birds are biological machines optimised for one purpose - converting feed to muscle as rapidly as possible - with welfare consequences that include chronic musculoskeletal pain from carrying excessive body weight on underdeveloped joints, cardiovascular systems overwhelmed by the demands of rapid growth, and metabolic disorders arising from organs unable to keep pace with muscle development. The suffering is not of brief intensity but of chronic daily experience across the bird's short life. Breed reform toward slower-growing genetics is the single most impactful intervention for broiler welfare.

What You Can Do

Choose chicken products with Better Chicken Commitment certification requiring slower-growing breeds
Advocate for retailers to commit to and honour Better Chicken Commitment timelines
Learn about the difference between conventional and slower-growing broiler welfare
Support welfare research into optimal growth rates balancing production efficiency and welfare