Laying Hen Keel Bone Fractures: A Widespread Welfare Problem

Why keel bone fractures affect the majority of laying hens in enriched colony cages and free-range systems and what can be done.

Key Facts

Keel bone fractures affect 50–80% of laying hens in enriched colony cages and up to 35% in free-range systems
The keel bone is the sternum — a prominent structural bone to which the wing muscles attach
Fractures cause chronic pain affecting perching, movement and access to resources
High-producing laying breeds have been selectively bred for egg production at the expense of bone density
Environmental factors including perch design, height and substrate contribute to fracture incidence
Keel fracture prevalence has increased as hens have been moved from battery cages — where it was rare — to more complex housing

Welfare Considerations

Keel bone fractures represent one of the most prevalent and under-addressed welfare problems in commercial egg production. The paradox is stark: welfare improvements that gave hens more space and perches inadvertently increased the incidence of a painful structural injury. Hens with fractured keels show altered movement patterns, reduced perch use and lower activity budgets — all consistent with chronic pain-driven behavioural suppression. The welfare cost affects the majority of the laying flock throughout the productive period. Addressing this requires a combination of genetic selection for better bone quality, perch design optimisation and possibly calcium supplementation during peak lay — but the industry has been slow to prioritise this despite its extraordinary prevalence.

What You Can Do

Support research into keel bone fracture prevention — donate to poultry welfare research organisations working on this specific problem
Choose eggs from producers who actively monitor keel bone fracture prevalence and publish their data
Advocate for keel bone fracture assessment to be included as a mandatory welfare outcome in laying hen assurance schemes
Engage with supermarkets to ask about keel bone fracture monitoring in their egg supply chains
Support selective breeding programmes that balance production traits with bone quality and structural health
Reduce egg consumption or switch to plant-based alternatives if welfare-certified eggs are unavailable at acceptable cost