Leg problems in fast-growing commercial broiler chickens are among the most significant and prevalent welfare issues in industrial poultry production, causing chronic pain in millions of birds.
Broiler lameness causes chronic, ongoing pain in affected birds. The selection of an analgesic-laced water source by lame birds in preference to plain water is compelling evidence that their lameness causes subjective pain they are motivated to relieve. Birds that are lame spend more time lying down, have difficulty accessing food and water, and may be trampled by more mobile flock mates. The 25-30% prevalence means hundreds of millions of individual birds experience leg pain during their short lives annually. The adoption of slower-growing breeds dramatically reduces this welfare burden while maintaining commercial viability.