Laying hens suffer epidemic rates of osteoporosis and bone fractures driven by the metabolic demands of egg production, representing a hidden but pervasive welfare problem in egg farming.
Hen bone welfare sits at the center of the egg welfare debate. The metabolic demands of producing 300 eggs per year are physiologically extreme — wild fowl produce a fraction of this number. The selective breeding that enables high production has created a metabolic vulnerability where calcium demands outpace dietary supply, systematically weakening bones. The irony of cage-free systems is that while they eliminate battery cage confinement welfare harms, they introduce new fracture risks from flight, collision, and perching. No current commercial egg system has fully resolved the bone welfare problem — it is embedded in the genetics of the modern laying hen.