Fast-growing broiler breeds selected for maximum growth rate cause chronic welfare problems. Breed reform using slower-growing breeds with better welfare outcomes is gaining momentum through corporate commitments.
Breed reform represents one of the highest-impact welfare interventions available in broiler production because it addresses multiple welfare problems simultaneously at their genetic root cause. Fast-growing breeds experience chronic leg pain from skeletal inadequacy relative to muscle mass, respiratory compromise from cardiac and pulmonary hypertrophy, and inability to thermoregulate effectively. Slower-growing breeds retain better proportionality between skeletal, cardiovascular, and muscular development, reducing these endemic welfare problems. The welfare difference is substantial and measurable: welfare outcome assessments at slaughter consistently show lower rates of hock burn, keel fractures, and lameness in slower-growing birds. The commercial barrier is the additional cost of slower growth - an estimated 5-20p per kilogram - which requires either consumer willingness to pay or retailer absorption. Corporate EBA commitments that create supply chain requirements drive adoption more effectively than individual consumer purchasing alone.