Light and feed management of broiler breeders reared under short versus natural day length

A series of four experiments was conducted to determine the response of meat-type breeder pullets to various light and feed management systems during the rearing, developing, and laying periods. Pullets reared under a short-day (8 h) lighting regimen entered lay at a significantly younger age and lighter body weight than did pullets reared under natural day length. When reared under short days, pullets subjected to light and feed stimulation earlier than 18 wk of age entered lay at a slightly younger age and significantly heavier body weight and produced fewer eggs through 45 wk of age. When pullets were reared under natural day length and photostimulated at 14 wk of age, incremental reductions in age (from 24 to 15 wk of age) at which feed stimulation was initiated resulted in proportionate reductions in age at first egg but had no effect on body weight at first egg. Results suggest that egg production by commercial meat-type females is optimum when managed to begin lay at 24 wk of age. Pullets reared under short days will enter lay at 24 wk if photostimulation is begun at 18 wk and feed stimulation is initiated not later than 24 wk. Pullets reared under natural day length will enter lay at 24 wk if photostimulation is begun at 14 wk and feed stimulation is initiated at 15 wk.