Fishmeal is very important protein source in poultry nutrition, mainly due to the high quality of the protein it supplies. This study was carried out to investigate the effects of formulating isonitrogenous and isoenergetic diets varying in fishmeal levels (0, 2.5 and 5% during the starter and 0, 1.25 and 2.5% during the grower period) on performance. A total of 264 Hubbard straight-run broiler chicks were allocated to each of these three dietary treatments which were replicated four times (22 chicks per pen) in a completely randomized design. Chick body weights, daily gain, feed intake and feed conversion ratio were determined at 10, 20, 32 and 42 days of ages. The results showed that the body weight at 32 and 42d, daily gain during 0-42d and feed intake during 11-20d, 21-32d and 0-42d significantly increased with fishmeal inclusion. In conclusion the results of this experiment indicated that the beneficial effects of fishmeal on broiler performance becomes most evident at higher use levels and during the latter growth periods, mainly via stimulation of feed intake.
