Effect of a combination of green and blue monochromatic light on broiler immune response

• The switching of green and blue light promote T and B lymphocytes proliferation.
• The switching of green and blue light enhance broilers immune responses.
• The switching of green and blue light alleviate the stress response in broilers.

Our previous study suggested that green light or blue light would enhance the broiler immune response; this study was conducted to evaluate whether a combination of green and blue monochromatic light would result in improved immune response. A total of 192 Arbor Acre male broilers were exposed to white light, red light, green light, and blue light from 0 to 26 days. From 27 to 49 days, half of the broilers in green light and blue light were switched to blue light (G–B) and green light (B–G), respectively. The levels of anti-Newcastle disease virus (NDV) and anti-bovine serum albumin (BSA) IgG in G–B group were elevated by 11.9–40.3% and 17.4–48.7%, respectively, compared to single monochromatic lights (P < 0.05). Moreover, the proliferation of peripheral blood T and B lymphocytes and the IL-2 concentration in the G–B groups increased by 10.4–36.2%, 10.0–50.0% and 24.7–60.3% (P < 0.05), respectively, compared with the single monochromatic light groups. However, the serum TNF-α concentration in the G–B group was reduced by 3.64–40.5% compared to other groups, and no significant difference was found between the G–B and B–G groups in any type of detection index at the end of the experiment. These results suggested that the combination of G–B and B–G monochromatic light could effectively enhance the antibody titer, the proliferation index of lymphocytes and alleviate the stress response in broilers. Therefore, the combination of green and blue monochromatic light can improve the immune function of broilers.