In the present study, the effects of the two lighting programs on the feed intake and growth performance, carcass quality, health performance as well as mortality of the Cobb 500 broiler chickens were studied. A near continuous lighting program of 23L: ID and a restricted lighting program of 12L: 12D were used. For this purpose, 17 959 birds were reared under a continuous lighting program of 24L: 0D from day 1 to day 14. At 15 days of age, the birds were randomly allocated to six houses. The houses were then randomly allocated to the two treatments with three replicates in a completely randomized design. The study lasted for 30 days after which the data on the feed intake, feed conversion efficiency, weight gain, final live weights, fat content, carcass weights, dressing percentages, incidences of leg disorders, mortality percentages due to ascites, sudden death syndrome and other causes of mortality as well as the total flock mortality percentages were analyzed using the t test for independent samples using SPSS Version 16. No significant differences were observed on the effects of the two lighting programs on the feed con version efficiency, weight gain, final live weights, fat content, carcass weights, dressing percentages, incidences of leg disorders, mortality percentages due to ascites, sudden death syndrome and other causes of mortality as well as the total flock mortality percentages. Significant differences were observed on the effects of the two lighting programs on the feed intak
