Layer Hen Keel Bone Fractures: A Hidden Welfare Crisis

Keel bone fractures affect 50-80% of laying hens in commercial systems and cause chronic pain throughout the laying period, representing one of the most significant and underrecognised welfare problems in egg production globally.

Key Facts

The keel bone is the large sternum of birds — in laying hens it is frequently fractured during normal laying activity.
Prevalence studies find 50-80% of hens in aviaries and enriched cages have fractured keels by end of lay.
Keel bone fractures cause chronic pain demonstrable through pain behaviour studies and analgesic treatment responses.
The primary cause is osteoporosis from calcium mobilisation for eggshell production, weakening the keel.
Perch design, height, and material affect fracture risk — round perches at appropriate heights reduce injury rates.
Genetic selection has identified hen lines with higher bone density that show lower keel fracture rates.
Keel fractures are rarely detected by farmers in commercial settings and receive no veterinary treatment.

Welfare Considerations

Keel bone fractures represent a welfare crisis hiding in plain sight in egg production. The majority of laying hens — across virtually all commercial housing systems, including those marketed as higher welfare — are living with chronic bone pain that is rarely acknowledged, monitored, or treated. The pain from keel fractures is real and measurable: hens with fractures show altered movement patterns, reduced time at perches, and respond to analgesics in ways indicating genuine pain relief. Addressing keel fracture welfare requires genetic selection for stronger bones, improved perch design, calcium nutrition optimisation, and honest inclusion of keel fracture prevalence in welfare assessments of egg systems.

What You Can Do

Advocate for keel bone fracture prevalence to be included as a mandatory welfare indicator in egg certification.
Support research into genetic lines with lower keel fracture rates and perch designs that reduce injury.
Choose eggs from farms participating in keel bone welfare research and improvement programmes.
Reduce egg consumption or choose plant-based alternatives to reduce demand for commercial laying systems.