Effect of combinations of monochromatic lights on growth and productive performance of broilers.

Our previous study suggested that green light promotes broiler growth during the early stage [posthatching day (P) 0 to P26], and blue light enhances growth during the later stage (P27 to P49). The purpose of this study was to improve broiler growth and productive performance by using a combination of monochromatic lights at critical points between the early and later stages of growth. A total of 512 male Arbor Acres broilers on P0 were reared under white light (W), red light (R), green light (G), and blue light (B) by using light-emitting diode lamps at 15 ± 0.2 lx from P0 to P26 (16 replicate pens/group, 8 birds/pen), and then switching to another color of light until P49 (4 replicate pens/group, 8 birds/pen). As compared with single monochromatic lights, broilers reared in environments under combinations of monochromatic lights, W→G, R→B, G→B, and B→G, attained heavier BW than those reared in environments under W→W (3.18 to 12.00%), R→R (1.96 to 18.14%), G→G (0.85 to 5.08%), and B→B (0.39 to 4.70%), respectively. In addition, feed conversion ratios in the W→B, R→B, and G→B combinations were lower than feed conversion ratios for W→W (15.86%, P < 0.05), R→R (18.41%, P < 0.05), and G→G (3.37%), respectively. Moreover, the eviscerated carcass weight and breast, thigh, and crus muscle weights under G→B were greater by 0.40 to 56.23% than were those for the other light groups except W→B (eviscerated carcass) and B→G (breast muscle). The results suggest that the application of the G→B and B→G exchanges can be used successfully to improve growth and productive performance in broilers.