The egg weight in the W light group was significantly (P < 0.05) greater than those in the R light group but were not significantly (P> 0.05) different in other light groups from 19 to 52 wk (Table 1).
The egg weight in W light was significantly (P < 0.05) greater than those in B light from 38 to 52 wk. Beginning at the age of 30 wk, the egg weight in W, B, and G light groups was consistently greater than those in the R light group throughout the remaining experimental stage (Figure 1A). These results were similar to the reports of Pyrzak et al. [4] for chicken but different from the reports of