Keel Bone Fractures in Laying Hens: A Hidden Welfare Crisis

Keel bone fractures affect the majority of laying hens in many commercial systems, yet they receive far less public attention than other poultry welfare issues. These fractures cause chronic pain and are closely linked to housing and perch design.

Key Facts

Studies across Europe find keel bone fracture prevalence of 50–80% in commercial laying hens, including cage-free systems
The keel bone runs along the sternum and is where the major flight muscles attach — fractures there are acutely painful
Fractures most commonly occur when hens collide with perches or other structures while landing or jumping
Hens with keel bone fractures show altered posture, reduced perch use, and behaviour consistent with chronic pain
The transition from enriched cages to cage-free systems was expected to improve welfare but keel fracture rates have not consistently decreased
Perch design, height, material (round vs. flat), and flock density all significantly affect fracture incidence
Genetic selection for bone strength is an emerging area of research as commercial breeds have been selectively bred for production at the cost of skeletal integrity

Welfare Considerations

Keel bone fractures are one of the most prevalent yet under-recognised welfare problems in commercial egg production. A hen with a fractured keel bone lives with chronic pain for the remainder of her laying life — which may be six months to a year after the injury. She cannot be individually treated in commercial flocks. Pain assessment studies confirm that fracture-affected hens show reduced activity, altered gait, and avoidance of behaviours that load the injury. The irony is that the move to cage-free systems — widely promoted as a welfare improvement — has not reliably reduced keel fracture rates, highlighting that housing type alone is not sufficient without attention to perch design and flock management.

What You Can Do

Support retailers and food companies that require keel bone fracture monitoring and reduction targets from their egg suppliers
Advocate for research funding into perch design, breed selection, and management practices that reduce fracture incidence
Choose pasture-raised or small-flock eggs from producers who can demonstrate active welfare monitoring
Support Compassion in World Farming and World Animal Protection campaigns that include keel bone fractures in their welfare scorecards
Reduce egg consumption or use plant-based alternatives where welfare concerns are a priority