57 Alexandria Journal of Veterinary Sciences www.alexjvs.com AJVS. Vol. 53: 57-62. April 2017 DOI: 10.5455/ajvs.263048 Manipulation of Broiler Growth Performance, Physiological and Fear Responses Using Three Monochromatic LED lights Radi A. Mohamed 1,5* , Sherif Z. El-Kholya 2 , Mustafa Shukry 3 , Seham El-Kassas 4 Nagham R. El Saidy 1 1 Depaertment of Hygiene and Preventive Med., Fac. Vet. Med., Kafr El-Sheikh Univ., Kafr El-Sheikh, Egypt 2 Department. of Animal Husbandry and Animal Wealth Development, Fac.Vet. Med., Damanhur Univ, Damanhur, Egypt 3 Department of Physiology, Fac. Vet. Med, Kafr El-Sheikh Univ., Kafr El-Sheikh, Egypt 4 Department. of Animal Wealth Development, Fac.Vet. Med., Kafr El-Sheikh Univ., Kafr El-Sheikh, Egypt. 5 Department of Aquaculture (Fish Welfare), Fac. of Aquatic and Fisheries Sci., Kafr El-Sheikh Univ., Kafr El-Sheikh, Egypt. ABSTRACT Key words: Behavior, Broilers, Fear Response, Monochromatic LED Light, Performance. The present study aimed to investigate the effect of rearing avian broiler under different monochromatic LED light color on their growth performance, physiological and fear responses. One hundred and thirty five unsexed day-old avian 48 chicks were randomly allocated into three light treatment (n=45 bird) each treatment 3 replicates (n=15 bird). The treatments were white, green, and blue light. The obtained results demonstrated that, broilers reared under blue and green light had higher body weight, weight gain, feed intake, carcass weight, carcass percent, hemoglobin, red blood cells, packed cell volume, total leucocytes count, lymphocytes, total protein, albumin, globulin and lower feed conversion ratio, bursa, liver, spleen relative weight, heterophils: lymphocytes ratio, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase compared with white light. Moreover, blue and green lights reared birds showed short tonic immobility duration and high levels of exploration in the open field test. In conclusion, rearing broilers under blue and green light for 23 h per day improve growth performance, physiological response, welfare, reduce stress and fear responses. Correspondence to: r.mohamed.vet@gmail.com 1. INTRODUCTION Many light sources are used in the field of poultry production as incandescent light, fluorescent light and light-emitted dioxide (LED). LED is a special unique light source of semiconductor diode which characterized by a very significantly longer life that may reach 100,000 h compared to other conventional light sources. Furthermore, monochromatic LEDs have small size, adjustable light intensity, specific wavelength, low thermal output and high photoelectric conversion efficiency, these benefits make LEDs very preferable light source in modern poultry management (Yang et al., 2016). Light considered as an important environmental factor for bird vision and modulation of physiological condition, growth performance, behavior and immune response (Rozenboim et al., 2004; Xie et al., 2008). Light duration, intensity, color and wavelength are very crucial factors in the growth performance of domestic fowl (Prayitno et al., 1997; Rozenboim et al., 2004). Varity of previous conducted studies demonstrate the effects of light criteria on bird health and immunity with special references to light color and spectrum, Rozenboim et al. (1999) found that maximization of monochromatic light effect on growth and welfare in broiler chickens is achieved by age of birds, also, Karakaya et al. (2009) found that rearing broiler under green light at an early age and blue light in older one could improve growth performance and meat quality properties, while, Rozenboim et al. (2004) stated that switching light from blue to green at 20 day age could improve growth performance of male broiler chickens. Moreover, Xie et al. (2008) found that immune response of broilers was enhanced under green and blue light.