Slow-Growing Broiler Breeds: Welfare Benefits and Trade-offs

Standard commercial broiler breeds grow so fast they experience chronic health problems. Slow-growing breeds take longer to reach market weight but have significantly better welfare outcomes.

Key Facts

Standard broiler breeds reach 2.5 kg slaughter weight in 33-35 days
Fast growth causes cardiovascular problems, skeletal disease, and chronic pain in 20-30% of birds
Slow-growing breeds defined under the Better Chicken Commitment reach weight in 56+ days
Slow-growing breeds have lower rates of hock burn, breast blisters, and gait impairment
Some retailers including M&S and Waitrose have committed to higher welfare breeds in their supply chains

Welfare Considerations

Standard commercial broiler breeds have been selected exclusively for growth rate and feed conversion efficiency, with no consideration for welfare. The result is birds that grow so fast their cardiovascular and skeletal systems cannot keep pace. Ascites (fluid accumulation from cardiac failure) affects millions of birds. Skeletal deformities cause painful lameness in a significant proportion of flocks. Slow-growing breeds, developed with some welfare characteristics in mind, have better leg health, lower ascites rates, and can perform more natural behaviours. The cost premium is real but modest — approximately 3-5 pence per chicken.

What You Can Do

Choose chicken labelled from higher-welfare breeds — RSPCA Assured chickens use slower-growing breeds
Support retailers that have committed to the Better Chicken Commitment
Engage with food companies about their timeline for switching to slower-growing breeds
Donate to organisations pushing for slow-growing breed adoption in supply chains
Reduce overall chicken consumption to create space for higher welfare products