Christmas, 1996 – Effect of Light Stimulation on Pullets

Two experiments were conducted in successive years to determine the performance of pullets lighted at 16, 18, or 20 wk. Pullets were grown on a step down protein feed formulation. Twelve hr of light/day were supplied through 12 wk. Thereafter, light was reduced to 10 hr/day. When pullets reached 16, 18, or 20 wk they were moved on to a laying house and subjected to natural daylight. At 20 wk all were placed on a stimulatory lighting program of 15hr/day. Onset of egg production, days to 50% production, egg production at 147 days, and body weight at 20 or 21 wk of age were significantly increased by delaying age at lighting. Neither egg weight nor feed intake were significantly affected during the laying period. Feed efficiency to 28 wk significantly improved when pullets were lighted at 16 wk of age. However, from 29 to 40 wk feed efficiency significantly improved for hens lighted at a later age. This improvement was not sufficient to offset results of late maturity that pullets lighted at 20 wk exhibited from 21 to 24 wk.