Figure 1. Body weight gain (g) in birds reared under different spectral composition.

Each group of treated birds was exposed to either white light, red light, yellow light, green light or blue light. Body weight was individually measured at 3, 4 and 5 week of age, and the body weight gain was calculated. Data are expressed as the mean value ± SD. ^a,bThe mean values without a common superscript indicates statistically significant differences (P < 0.05).