Research Note: Performance of Broiler Breeders Reared Under Different Lighting Regimens

Abstract

Two groups of broiler-breeder pullets were reared to 4 wk of age with 23 h of light per day (5.4 lx). At4 wk of age, one group of the pullets was placed in a dark-out house and provided with 8 h of light (5.4 lx at bird level) until they were 18 wk of age followed by 10 h of light to 20 wk of age. At 20 wk of age, they were provided with natural light (approximately 200 to 400 lx) until they were 22 wk of age, 14 h of light to 24 wk of age, 15 h of light to 40 wk of age, 16 h of light to 49 wk of age, 17 h of light to 59 wk of age, and 18 h of light until the end of the experiment at 72 wk of age. At 4 wk of age, the other group of pullets was placed in a lighted house and gradually reduced from 23 h (approximately 200 to 400 lx) to 15 h of light per day at 24 wk of age. Subsequently, they received the same amount and intensity of light as the pullets in the dark-out house. Pullets were weighed at regular intervals and fed the amount of feed necessary to retain the BW recommended by the breeder. During the rearing period, the pullets in the dark-out house consumed significantly less feed per pullet (P<.05) than did those in the lighted house. The cumulative hen-day egg production of the pullets reared in the dark-out house was significantly (P<.05) higher for the first five 28-day periods than it was for the pullets reared in the lighted house. Hatchability was significantly higher (P<.05) for the pullets reared in dark-out but only for the first hatch. The pullets reared in dark-out had significantly better (P<.05) feed utilization (kilograms of feed per dozen eggs) and higher mortality in the laying house than did the pullets reared in the lighted house.