Farm Animals

Laying Hen Keel Bone Fractures: A Major Welfare Problem in Cage-Free Systems

Keel bone fractures affect over 50% of laying hens in some cage-free aviary systems. Understanding causes and solutions is critical to realising the welfare potential of the cage-free transition.

Key Facts

The keel bone (sternum) is fractured or damaged in 50-80% of hens in some aviary systems
Fractures occur during flight, landing, collisions with perches, and handling
Keel bone fractures cause chronic pain affecting roosting, feeding, and social behaviour
Breed selection, perch design, and litter management influence fracture rates significantly
Slower-feathering genetics and modified landing perches reduce fracture incidence
Radiography is the gold standard for fracture detection but rarely used commercially

Welfare Considerations

Keel bone fractures represent a major unresolved welfare problem in the cage-free transition. Moving from battery cages to aviaries addresses behavioural restriction but introduces musculoskeletal injury. The pain from keel fractures is poorly assessed and undertreated. Solutions exist through breed selection, housing design, and management but require investment. Welfare certification schemes must incorporate keel bone fracture monitoring as a mandatory outcome measure.

What You Can Do

Support laying hen welfare campaigns that include keel bone fracture as a key metric
Choose eggs from farms demonstrating low fracture rates in welfare assurance data
Advocate for mandatory keel bone fracture monitoring in laying hen farm assurance schemes