Laying Hen Keel Bone Fractures | Animal Welfare Hub

Keel bone fractures are the most prevalent welfare problem in commercial laying hen systems, affecting over half of birds in some flocks.

Key Facts

The keel bone (sternum) is fractured in 50-80% of hens in aviaries and 15-30% in enriched colony systems.
Fractures occur from collisions with perches, falls, and physical impacts during normal flock activity.
Fractured keels cause chronic pain, altered posture, and reduced ability to access food and water.
Bone mineralisation for eggshell production competes with skeletal strength, predisposing hens to fracture.
Selective breeding for lower keel fracture rates has shown promise as a long-term solution.

Welfare Considerations

Keel bone fractures represent a chronic pain welfare crisis in commercial egg production. Research using pain assessment tools confirms that hens with fractured keels experience persistent nociceptive pain. Paradoxically, aviary systems that provide perches and more space for natural behaviour have higher fracture rates than enriched cages due to collision and fall risks. This creates a difficult welfare trade-off. Interventions being investigated include better perch design, improved litter conditions to cushion falls, and genetic selection for stronger bones. Until solutions are developed at scale, keel bone fracture represents an unresolved welfare challenge across all housing systems.

What You Can Do

Support research into keel bone fracture prevention in laying hen systems.
Advocate for keel bone fracture to be treated as a priority welfare indicator in farm assurance.
Choose eggs from producers actively tracking and reducing keel bone fracture rates.
Engage with retailers to demand transparency on keel bone fracture prevalence in their supply chains.