Green light during rearing does not significantly affect the performance of egg-type pullets in the laying phase

Lohmann White pullets were reared in cages and illuminated with 8 h of white light at 2.6 lx or green light at 3.0 lx from commercial incandescent lamps. They were transferred to individual cages and the photo-period was increased to 14 h of white light at 15, 17, or 19 wk. Pullets grown under green light had significantly lighter BW at 6 wk than did birds grown under white light, but BW were similar at 12, 15, 17, and 19 wk. Although mean age at first egg was 1 d earlier for birds reared under white light, there were no significant differences between the 2 groups for any other performance trait. These findings do not support lamp manufacturers' claim that green fluorescent light during rearing improves performance. As expected, the birds photostimulated at 17 wk matured after the 15-wk birds but before the 19-wk birds. Subsequently, the 15-wk birds laid more eggs to 71 wk, but had a lower mean egg weight and thinner shells (higher deformation) than the other 2 groups. Albumen height and feed intake were similar for all 3 photo-stimulation ages.