The present study was under taken to investigate the effect of substitution of fish meal which is comparatively costly protein supplement with cheaper cotton seed meal on performance of broiler chicks. As one hundred and eighty Star Bro day old broiler chicks were reared on five experimental rations upto 50 day of age. The control ration contained 12 % fish meal (100 %) which was replaced by the cotton seed meal at 0, 4.17, 7.39, 11.03 and 14.72 % level (0, 25, 50, 75 and 100% on Protein equivalent basis). The starter rations were fed upto 28 days of age and finisher rations were fed upto 50th day.

Results revealed however non significant difference among weight gain of chicks fed on different experimental starter rations. But significant differences among weight gain of chicks fed on finisher rations were noticed.

The chicks fed on rations containing 100%,75%, 50% and 25% fish meal were heavier as compared to those chicks fed on rations in which fish meal was replaced by cotton seed meal on protein equivalent basis. Non significant differences in total weight gain were noticed amongst chicks fed on different experimental rations. highly significantly more feed was consumed by the chicks fed on starter and finisher rations containing 100%, 75%, and 50% fish meal as compared to those chicks fed on other experimental rations. Apparently better feed utilization in chicks were noticed by addition of cotton seed meal at different levels i.e 4.17, 7.39 and 11.03 % in the starter and finisher rations. However non significant differences among the feed efficiency values were observed in chicks fed on various experimental rations. However dressing % of all the birds fed on different rations was found non significant. Present study indicated that addition of cotton seed meal did not significantly effect the growth rate, however, slightly decreased growth rate was observed with progressive increase of cotton seed meal in the ration. Feed efficiency was comparable with that of fish meal. Results also indicated that ration containing cotton seed meal were comparatively cheaper and cost per Kg of live weight was decreased. Therefore, net profit per chick was greater.