Figure 8. Fertility of eggs produced by birds exposed to different spectral composition.

Each group of treated birds was exposed to either white light, red light, yellow light, green light or blue light. A total of 1,000 labelled eggs from 6 light-treated group were hatched in the same incubator under the controlled conditions of 37.5 °C and 55% relative humidity. These eggs were candled twice on the 7th and 14th days to remove unfertilized and dead-germ eggs to measure fertility. Data are expressed as the mean value ± SD. ^a,bThe mean values without a common superscript indicates significant differences (P < 0.05).