Keel Bone Fractures in Laying Hens

Keel bone fractures affect up to 80% of laying hens in some commercial systems, causing chronic pain that significantly compromises welfare and challenges the welfare credentials of even cage-free production systems.

Key Facts

Studies in the UK and EU find keel bone fracture prevalence of 50-80% in commercial laying hens across all housing systems including free-range
Keel bones fracture from collisions with perches, falls from height, or during landing, particularly in flocks with poorly designed perch systems
Fractured keel bones cause chronic pain evidenced by altered movement, posture changes, reduced perch use, and grimace scale responses
Keel bone fractures are more common in free-range and aviary systems than in enriched cages due to increased movement and collision opportunities
Selective breeding for bone strength alongside egg production traits is being investigated as a long-term genetic solution
Perch design, height, diameter, and surface texture all significantly affect keel bone fracture rates
The welfare cost of keel bone fractures challenges the narrative that cage-free automatically means higher welfare without attention to housing design

Welfare Considerations

Keel bone fractures represent one of the most significant and underappreciated welfare problems in laying hen production. Unlike visible conditions, the pain from fractures is hidden — hens continue to function despite chronic discomfort, making the problem easy to overlook at farm level. The prevalence across all housing systems, including free-range, challenges simple assumptions that removing cages resolves hen welfare. The welfare case for cage-free production remains valid, but it must be accompanied by attention to housing design, perch specification, and management practices that reduce collision and fall risk. Research into fracture-resistant genetics and perch design standards that reduce keel bone damage is urgently needed at both industry and regulatory level.

What You Can Do

Support welfare standards that include keel bone assessment alongside other hen welfare indicators
Engage egg producers and retailers about their monitoring of keel bone fracture prevalence in supplying flocks
Advocate for perch design standards that minimise keel bone collision risk in cage-free systems
Support research into laying hen breeds with better bone strength alongside productive traits
Ask egg certification bodies about their keel bone welfare requirements and monitoring protocols
Donate to organisations researching keel bone fracture prevention and early detection
Share information about keel bone welfare with people who assume cage-free eggs are comprehensively higher-welfare