Keel bone fractures affect over half of laying hens in many production systems and cause chronic pain. This hidden epidemic of skeletal injury is one of the most numerically significant welfare issues in commercial egg production.
Keel bone fracture welfare is among the most significant and underappreciated issues in commercial egg production. The sheer scale — affecting hundreds of millions of hens across Europe alone — makes this one of the largest sources of chronic pain in farmed animals. Hens with fractured keels show pain-consistent behavioural changes detectable by trained observers, and preference tests confirm they seek analgesia when available. The transition from battery cages to enriched and aviary systems — motivated by welfare concerns — paradoxically increased keel fracture rates because hens now use perches and have room to fly, increasing keel loading. Interventions with proven effectiveness include lower perch heights, padded perch materials, and ramps rather than abrupt drops. Genetic selection for keel robustness is the most sustainable long-term solution and is receiving increasing industry investment. Welfare certification schemes should mandate keel bone inspection at slaughter as an audit metric.