effect of lighting programs on performance, carcass and production costs of arian broilers

. light is an environmental factor, which has profound influences on broilers performance and frequently overlooked management practices. this study was conducted to compare the effects of different lighting programs on growth, carcass parts and economical performance using 320 one day–old broilers (arian 386) in completely randomized design with 4 treatments and 8 replicates per each treatments (10 birds for each replicate). the four lighting schedules under study were: 1- continuous lighting (control), 2- decreasing-sudden increasing lighting, 3- decreasing-gradual increasing lighting and 4- intermittent lighting (1 light: 3 dark). feed intake, body weight, feed conversion ratio, mortality and production index of birds raising under different lighting schedules were compared during six weeks of experimental carrier. final body weight and total feed consumption were the same for all birds regardless of lighting schedules applied (p>0.05). intermittent lighting significantly improved feed conversion ratio and decreased mortality rate compared to other lighting schedules (p 0.05).the highest economic profit was related to intermittent lighting schedule group (p<0.05). in conclusion, it seems that implication of some limitation in lighting hours is a practical tool for promotion of broilers performance and furthermore would reduced production costs and will promote economic profits. the results of this experiment emphasized the application of intermittent lighting schedule for arian broilers.