Laying Hen Bone Health and Keel Fracture Welfare

Keel bone fractures are endemic in laying hens across all production systems, causing chronic pain in a high proportion of the global laying hen population. The scale of this welfare problem is only recently being fully recognised.

Key Facts

Keel bone fractures affect an estimated 50-80% of laying hens in commercial production, varying by system
Contrary to expectation, enriched colony cage and free-range hens show similar or higher fracture rates than battery cage hens
The keel bone runs along the sternum and provides attachment for flight muscles - fractures occur from collisions and falls
Hens with keel fractures show reduced feeding behaviour, altered posture, and pain indicators in grimace scale assessments
Calcium depletion from intensive egg production weakens bones, increasing fracture risk
Aviary systems, while better for many welfare parameters, expose hens to falls from higher perches that increase fracture risk
Selective breeding for keel bone strength, improved perch design, and lighting management can reduce fracture incidence
The UK's Farm Animal Welfare Council raised keel fractures as a priority welfare issue requiring urgent research and management response

Welfare Considerations

Keel bone fractures represent a largely invisible but enormous welfare burden on the global laying hen population. A majority of laying hens in commercial production globally - billions of individual birds - are living with chronic bone pain from keel fractures that are not diagnosed, treated, or even recognised as a welfare problem. The perverse finding that free-range and enriched systems can have higher fracture rates than cages reflects the complexity of this problem - improved freedom of movement creates collision and fall risks that cause the very fractures that better housing was meant to prevent. Addressing keel fractures requires simultaneously improving housing design, breeding for bone quality, and nutritional management of calcium status.

What You Can Do

Support egg producers investing in keel fracture research and management programmes
Advocate for keel fracture prevalence to be a mandatory welfare monitoring metric for egg producers
Engage with egg welfare certification bodies to include keel fracture assessment in their standards
Support research into perch design, lighting management, and genetic selection approaches that reduce fracture incidence
Choose eggs from producers who have keel fracture monitoring programmes and transparent data
Reduce egg consumption or engage actively with producers about their keel fracture management strategies