author(s)
P Gautam, PS Pramanik, KD Singh, MK Verma, S Gautam, AK Verma, VN Gupta and B Singh

abstract
The present experiment was conducted to investigate the impact of blue and green monochromatic light in comparison to white LED on the stress reaction and mortality rate of broiler chickens. For a period of 42 days study two hundred forty day old Vencobb 400 straight run commercial broiler chicks were randomly divided into three groups with 2 replicates of 40 in each at the poultry unit of livestock farm complex, College of veterinary sciences and animal husbandry, A.N.D.U.A.T. Kumarganj, Ayodhya, (U.P). In first green-blue group (T_GB), the birds were kept on green LED light (GL) and blue LED light (BL) from 1-21days and 22-42 days, respectively. The broiler birds of Group T_W and T_C were kept in white and incandescent LED lights for 42 days, respectively. The findings revealed that the heterophil % differed significantly (P<0.05) at 6^th week of age when broiler finished their light treatment duration (after shifting from green LED to blue LED at 4^th week of age). The ratio of blood heterophil to lymphocyte was also significantly differed (P<0.05) at the 6^th week of age. The H/L ratio was higher in T_C group (0.37±0.008) whereas, it was lowest in T_GB group (0.33±0.456) than T_W group (0.35±0.120) birds at 6^th of age. This study indicated that birds were minimum stress level in T_GB group than other treatment groups. The mortality rate of broiler chicks was highest in T_W group (6.25%) and lowest in T_GB group (3.75%) than T_C group (5%) birds. The results of the present study concluded that, broiler birds under green-blue (1-21d in GL and 22-42d in BL) LED bulb treatment group had significantly (p<0.05) lower stress as drawn by a ratio of Heterophil: Lymphocyte, which was highest in incandescent bulb treatment groups followed by white LED groups.