Layer pullets are first placed in cages or open-floor environments for six to eight weeks. Floor-reared birds are transferred to rearing cages until ready for production. All layer pullets are then reared in cages until they are 18 to 20 weeks of age, after which they are transferred to production housing. Laying flocks are held in production until about 75 weeks of age. Commercial layers are confined to cages (three to four birds per cage) within buildings. Rows of cages are most often tiered three to four cages high, each tier slightly offset from the one below to prevent droppings.
