Abstract: 【Objective】 Using LED (light-emitting diodes) as light sources, our study was to compare AA (Arbor Acres) development and productive performance with the monochromatic light and discuss the internal mechanism. 【Method】 Day-old 264 male broilers were divided into four light treatments (n=60), control white (400 nm-700 nm), red (660 nm), green (560 nm) and blue (480 nm) by using LED. There were 3 replications for each light treatment. Feed and water were provided for ad libitum consumption. Light intensity was 15 lux at the height of birds’ heads and scheduled for 23h of light and 1 h of dark during the entire experiment. 【Results】 The results showed that body weight in both groups of blue and green light were higher than that of red and white light groups (6.86 %-10.75%, P<0.05) during the early stage (0-26 day of age) all along. Meanwhile the feed conversion ratio of green light group (1.8) was the lowest in all groups. Body weight of blue light group was the highest during the late stage (27-49 day of age). At the 49 day of age, body weight of blue light group was higher than other groups (17.87 %, P<0.05). Carcass, breast muscle, thigh, crus and net chamber of blue light group were higher than others (14.39%-19.86%, P<0.05) and feed conversion ratio (2.12) was the lowest. Using radioimmunoassay to determine serum testosterone concentration, we found testosterone level was increased following by age during the early stage and it reached the peak at 21 day of age; however, it was decreased slowly in various groups during the late stage. But testosterone level of green and blue light groups was higher than that of red and white group (35.37%-37.13%, P<0.05) during the early stage, but that of blue light group was higher than others during the late stage (14.36%-28.77%, P<0.05). 【Conclusion】This study indicates broiler’s growth and productive performance would be increased when who was illuminated with green or blue light at the early stage and blue light at the late stage under 15 lux light intensity. This concerns that blue and green light were more effective to stimulate to secrete testosterone.

Key words: Broiler, Monochromatic light, Growth, Productive performance, Testosterone