Broiler Genetics and Welfare: The Case for Slower-Growing Breeds

The genetics of commercial broiler chickens have been selected almost exclusively for growth rate, causing widespread health problems. Transitioning to slower-growing breeds is a foundational welfare improvement.

Key Facts

Modern broiler chickens have been selectively bred to grow three times faster than breeds from the 1950s
The rapid growth rate causes skeletal disorders, cardiovascular problems, and ascites in a significant proportion of birds
Studies show that 25-30% of conventional broilers experience gait problems severe enough to affect normal walking
Slower-growing breeds reaching market weight in 56+ days show substantially lower rates of leg disorders and mortality
The Better Chicken Commitment requires adoption of breeds meeting minimum welfare criteria including slower growth
European regulators and retailers are increasingly mandating slower-growing breeds as baseline welfare standards
The economic cost of transitioning to slower-growing breeds is estimated at approximately 10-15% of production cost
Some slower-growing breed systems achieve comparable profitability through lower mortality and medication costs

Welfare Considerations

The genetic foundation of modern broiler production is a welfare problem that cannot be solved by enrichment alone. A bird that grows so fast its skeleton cannot support its weight will suffer regardless of how many perches and bales are provided. Slower-growing breeds represent a fundamental correction to decades of one-dimensional selection that prioritized feed conversion and growth speed over animal health. The transition requires investment and industry courage, but the welfare gains are substantial and the economic case is increasingly compelling as mortality and medication costs in slow-growing flocks are factored in.

What You Can Do

Prioritize chicken products from companies using breeds meeting Better Chicken Commitment welfare criteria
Ask chicken brands directly which breed standards they apply and when they plan to complete transitions
Support supermarkets that source exclusively from farms using slower-growing or welfare-certified breeds
Reduce chicken consumption or shift to plant-based alternatives where welfare-certified options are unavailable
Advocate for regulatory adoption of breed welfare criteria as minimum legal standards in poultry production
Support research on optimizing slower-growing breed systems for both welfare and production efficiency