Effect of Vitamine Supplementation and feeding Rate and Time on Fish Performance, Under Egyptain conditions

The aim of the present work was to study the effect of feeding rates and vitamin C and E supplementation and their interaction on growth performance of Nile tilapia (Oreochromis niloticus).Fish were divided into eight groups, each group of fish was stocked into 3 aquaria and each contains 10 fish. The fish of the first four groups were fed diet at the level 3% of live body weight; other four groups were fed diets at the level 5% of live body weight. Within each dietary level, first fish group was fed diet without any supplementation, the second group was fed diet supplemented with 50 mg vitamin C/kg diet, the third group was fed diet supplemented with 25 mg vitamin E/kg diet and the fourth group was fed diet supplemented with 50 mg vitamin C and 25 mg vitamin E/kg diet. Final live body weight and daily weight gain of fish significantly (P<0.001) increased by 61.85 and 72.28% when fish fed at the high feeding rate as compared with those fed at the rate 3% of body weight daily. Feed conversion impaired with increasing feeding rate by 49.33% when compared with fish fed the low feeding rate. Fish fed 5% feeding rate recorded lower final margin by 55.51% than those fed diet at the feeding rate of 3%. Final live body weight increased by 11.18, 26.24 and 26.01%, respectively in fish fed diets supplemented with vitamin C, E and C + E mixture, when compared with fish fed diet without vitamin supplementation. Also, daily weight gain increased by 13.79, 30.17 and 30.17%, respectively). Final margin was increased by 46.93, 82.17 and 106.67%, respectively. The best final margin was obtained in fish group fed diet supplemented with vitamin C + E.