Laying Hen Keel Bone Fractures | Animal Welfare Hub

Keel bone fractures affect the majority of laying hens in commercial flocks, causing chronic pain that impairs movement, feed access, and quality of life, and representing one of the most pressing unsolved welfare problems in poultry production.

Key Facts

The keel bone is the central chest bone of birds; fractures occur in 50-80% of laying hens in enriched cage and free-range systems
Keel bone fractures are caused by collisions with perches, nest boxes, and other housing structures, and by calcium mobilisation for eggshell production
Hens with keel bone fractures show altered posture, reluctance to use perches, reduced activity, and reduced feed intake
Pain assessment studies confirm that keel bone fractures cause significant ongoing pain: hens with fractures self-administer analgesics when given the choice
Paradoxically, keel bone fracture rates are higher in free-range and aviary systems than in conventional cages, due to collision and falling risks
Perch design, height, and surface texture significantly affect collision fracture rates — padded, lower, angled perches reduce fractures
Genetic selection for keel bone strength is technically feasible and is under investigation as a long-term solution

Welfare Considerations

Keel bone fractures represent a chronic welfare problem that affects the majority of hens regardless of housing system. The pain of a fractured keel bone — confirmed by analgesic self-administration studies — impairs normal behaviour including perch use, social interaction, and feed access throughout the laying period, which may last 12-18 months. The welfare community faces a genuine dilemma: free-range systems offer important welfare improvements (space, natural behaviour) but create new fracture risks. The solution is not to abandon enriched systems but to invest in perch design improvements, genetic selection for bone strength, and nutritional strategies that reduce the calcium deficit driving osteoporosis. This is an active and important area of welfare research.

What You Can Do

Support laying hen welfare research organisations working on keel bone fracture prevention
Ask egg producers and retailers about their keel bone monitoring and fracture prevention strategies
Advocate for inclusion of keel bone fracture prevalence in welfare audit schemes and labelling standards
Donate to Compassion in World Farming or similar organisations funding perch design and hen bone health research
Choose eggs from producers who actively monitor and report keel bone health in their flocks