The chicken eye can discriminate light color, and different light wavelengths affect egg quality.
In this study, we used blue (B), green (G), and red (R) light produced by light-emitting diode
lamps, as well as incandescent light (W) to illuminate Hy-Line Brown hens from 19 to 52 wk. All
light sources were equalized to a light intensity of 15 lx and applied for 16 h daily. The results
showed that egg weight in W light (61.1 g) was significantly (P < 0.05) greater than those in R
light (59.2 g) throughout the experimental stage. Beginning at the age of 30 wk, egg weight in R
light was consistently smaller than those in other lights. The egg length in B light was significantly
(P < 0.05) shorter than those in other lights, and its width was significantly (P < 0.05) shorter than
those in W light from 38 to 52 wk. The egg width in R light was significantly (P < 0.01) shorter
than those in W light and to a lesser extent (P < 0.05) shorter than those in B and G lights from
19 to 52 wk. Similarly, eggshell strength in G light was significantly (P < 0.01) better than those
in W and B lights, and eggshell thickness in G light was significantly (P < 0.05) better than those
in other lights from 21 to 45 wk. Our results indicate that egg weight in R light was less than
those in other lights, the egg length and egg width in B light became shorter, and the egg width
in R light became shorter with age; the egg quality in G light was found to be the best.