The effect of light wavelength on the production and quality of eggs of the domestic hen

The effect of light color on egg-laying and on egg quality during the first 50 wk of egg production and during a second cycle of 19 wk following molting was examined. Hens were exposed to one of the following six sources of light: blue (B), green (G), red (R), tungsten (T), cool-white (C) fluorescent or simulated-sunlight (V) fluorescent tubes. Light intensity was equalized at photon output. Total egg production per hen was significantly influenced by the color of light with the most eggs being procuced in R light and the fewest in B light. Hens were more sensitive to light color in response to egg production during the second cycle than during the first cycle. Hens in C light produced significantly fewer eggs than those under V light in both laying cycles. Eggs laid under B or G light were consistently larger than those under R light. Egg weights of hens in V light were heavier than those for the C or T light groups. In the first cycle, shell quality was significantly better in G light than in B or R light. Percent of yolk increased and percent of albumen decreased with age during the first cycle in all treatments and the rate of change was directly related to light color (wavelength). In the second cycle, shell quality, percent of shell, yolk and albumen did not change significantly with age in any of the light treatments. It can be concluded that the wavelength of light may influence egg production, egg components and shell quality of the domestic laying hen.