Keel bone fractures are among the most prevalent welfare problems in commercial egg production. Understanding why they occur and how to prevent them is critical for improving hen welfare at scale.
Keel bone fractures represent a systemic welfare failure across egg production systems. While battery cages prevent the falls that cause fractures, they impose severe restriction on movement — replacing one welfare problem with another. Cage-free systems allow natural behavior but dramatically increase fracture rates due to perch design, flock density, and hen genetics. Research identifies key risk factors: perch height and angle, litter quality, stocking density, and breed genetics. Sloped perches at appropriate heights significantly reduce fracture rates. Breeding programs are beginning to select for bone strength alongside egg production metrics. Pain assessment in hens remains underdeveloped — birds hide pain as prey animals, making subclinical suffering widespread and underdiagnosed.