This study was carried out to investigate the effect of duration of feeding starter (0-11, 0-16 and 0-21 days) and grower diets (11 -35, 16 -35 and 21 - 35days) on final broiler performance to 42 days of age. A total of 320 mixed broiler chicks (Ross 308) were allocated to three dietary regimens in a completely randomized design (4 replicate /each 20 chicks). Chick body weight, feed intake and feed conversion ratio were determined at 11, 16, 21, 35 and 42 days of ages. The results showed that the duration of feeding the starter and grower diets had no significant effect on broiler liveweight, feed intake and feed conversion ratio. The relative weight (%) of breast meat, abdominal fat, intestinal weight and length, and liver were not significantly affected by dietary treatments. Considering the fact that the typical cost of a starter diet is much greater than a grower diets, replacing the starter diets at an earlier age may have significant economic benefits on broiler production. Key words: Broiler; grower; finisher; performance; starter
