ABSTRACT:The current study aimed to evaluate the effects of exposing pre-mature Dandarawi roosters to different light-emitting diode (LED) light colors on testicular development, serum testosterone levels, and sperm motility and velocity. Seventy-five roosters, 16 weeks old, were assigned to 5 experimental groups each with three replicates of five birds per pen. Roosters of each experimental group were subjected to a different light colorusing Nine-watt red, yellow, green, blue and white LED bulbs from 16 to 36 weeks of age. Twenty-five semen pools were obtained over the last ten weeks (5 pools from each treatment) to evaluate sperm motility and velocity. Blood serum was collected to evaluate testosterone levels and the testicular growth was assessed. The results showed that green light hindered the testicular growth and had adverse effects on almost all studied semen traits (P<0.05). Both green and blue light significantly lowered circulating testosterone levels compared to other experimental groups (P<0.0001). Roosters subjected to red light exhibited significantly higher percentages of total and progressive motile spermatozoa, a greater number of spermatozoa per ml, higher values of curve linear velocity (VCL), average path velocity (VAP) and straight linear velocity (VSL) and finally lower percentages of slow sperm as compared with roosters exposed to green, blue and white light. Roosters exposed to yellow light showed comparable results of testicular growth, serum testosteroneconcentrations and percentages of total motile, progressive and rapid spermatozoa to those exposed to red light. These results indicate that red and yellow light has better effects on reproduction and sperm quality than white and blue light, and thatgreen light imposes adverse effects on reproduction in Dandarawi roosters.