Evaluation of replacing fish meal with corn protein concentrate in Nile tilapia Oreochromis niloticus fingerlings commercial diet

Four isocaloric-isonitrogenous diets containing 0, 50, 100 and 190g/kg corn protein concentrate (CPC) as replacement for dietary fish meal were fed to Nile tilapia Oreochromis niloticus fingerlings for 8weeks. Tilapia growth parameters were not significantly (p>.05) different in fish fed diets with 0, 50 and 100g/kg CPC and found to be superior compared to those fed on 190g/kg CPC. Fish dressing ratios and body composition were similar among all treatments. The electron microscope indicated that the stomach size of control fish was slightly smaller and the wall was thinner while the stomach of the fish fed all other levels of CPC undergone a remarkable size increase and their walls were thicker after feeding diets with CPC. Total aerobic bacterial and coliform counts were significantly decreased in fish intestine when fed diets with 100 and 190g/kg CPC compared with fish fed diets with 0g/kg or 50g/kg CPC. This study indicates that it is possible to replace up to 534g/kg of dietary fish meal in tilapia fingerlings using 100g/kg of CPC without any negative effect on fish growth and proximate body composition.