Commercial laying hens are slaughtered at around 72 weeks when egg production becomes uneconomical. The welfare of hens at end of lay and during transport to slaughter raises important questions often overlooked in welfare discussions.
End of lay hen welfare represents a major welfare concern due to scale and the physical condition of affected birds. Years of intensive egg production depletes calcium from bones, causing osteoporosis so severe that routine handling causes fractures. End of lay hens transported to slaughter therefore experience pain from bone fractures occurring during catching and loading. Their low commercial value means less investment in careful handling. The killing of 7 billion male chicks annually at hatch is a separate but related issue, as male chicks from laying breeds have no commercial value in the egg industry. In-ovo sexing technology enabling sex determination before hatching is being adopted by some producers, offering a welfare improvement by eliminating hatch-day killing.