Laying Hen Keel Bone Fracture Welfare

Keel bone fractures affect a majority of laying hens in commercial systems and cause chronic pain that represents one of the largest-scale welfare problems in modern agriculture.

Key Facts

An estimated 50-80% of laying hens in cage-free and free-range systems have fractured keel bones
The keel bone is the breastbone to which flight muscles attach — it is essential for wing movement
Fractures occur primarily from collisions with perches and equipment during flight in large, multi-tier houses
Fractured keel bones heal poorly and cause chronic pain that persists for weeks to months
Cage-free systems, while better for many behavioral needs, have not reduced keel fracture prevalence compared to enriched cages

Welfare Considerations

Keel bone fractures represent a serious welfare problem hidden within what is often promoted as the welfare solution — cage-free hen housing. The irony is painful: hens who have the freedom to fly and perch in multi-tier aviaries experience higher fracture rates than those in enriched cages, because they collide with structures. Fractures cause chronic pain that persists throughout the production cycle. Solutions being actively researched include improved perch design, better lighting to reduce collision risk, slower-growing breeds with stronger bones, and routine monitoring programs. The scale of the problem — affecting hundreds of millions of hens globally — demands urgent attention.

What You Can Do

Support research and advocacy for hen housing systems that meet behavioral needs without causing keel fractures
Choose eggs from producers with documented keel bone monitoring and low fracture prevalence
Engage with egg certification standards bodies to prioritize keel bone welfare in their requirements
Reduce egg consumption or source from small-scale local producers with demonstrably good welfare outcomes
Advocate for mandatory keel bone fracture monitoring as a welfare performance indicator in laying hen production