The effects of red and white light during the prebreeder and breeder periods on egg production and feed consumption in Large White turkey.

Large White turkey hens were conditioned with 5 lx of white or red incandescent light from 20 to 32 weeks of age. Hens from both of these groups were given white or red incandescent light at two intensities (approximately 85 and 160 lx) during a 20-week breeder period. Feed consumption was greatest for hens no white light during the prebreeder period (P less than or equal to .01), but hens on red light consumed the greatest amount of feed during the breeder period. The only consistent finding concerning egg production was the hens exposed to high intensity (160 lx) white light, regardless of whether the prebreeder light was white or red, had the poorest egg production (P less than or equal to .01). It is concluded that red light during the prebreeder or breeder periods is not beneficial for egg production over that achieved with low intensity white incandescent light, and that bright white incandescent light is deleterious to egg production.