Water-Soluble Vitamin Requirements of Tilapia (Sarotherdon Mossambicus Peters and S. niloticus Linnaeus)

Abstract

Water-soluble vitamin requirements of tilapia (Sarotherodon mossambicus Peters and S. niloticus L.) were evaluated. Fish were maintained between 25 - 270C and weighed weekly. All diets were isocaloric and prepared from semi-purified constituents with a vitamin-free casein. Data from fish performances, development of deficiency symptoms, analyses of proximate fish carcass composition, enzyme assay (GOT, GPT for pyridoxine test), and mineral contents of fish were used in correlating their vitamin requirements. Poor growth, high and variable FCR and lowered SGR were obtained in CAP, BIO, Rib, B12 deficient fish. Dietary deficiency of B6, Th- and BIO were reflected in increased sensitivity, convulsions and high mortality in fish. Fish reacted early to their dietary deficiencies and such behavioural symptoms could be used in diagnosing them. Survival of fish was greatly enhanced with adequate supply of B6, Th-, BIO, CAP, ASA, and Rib. Metabolic disturbances and poor tissue mineralization characterised dietary deficiency of ASA, CAP, Th-, BIO, NA, B12, and B6 which were discussed in relation to the economics of fish culture and the acceptance of fish by the consumers. Blood composition of fish was adversely affected in NA, FA and B12 deficiency states. Excessive dosing of tilapia with water-soluble vitamins produced no adverse effect except in the case of B6 which resulted in depression of growth; however, the use of a high vitamin concentration could be expensive. Dietary supplementation of water-soluble vitamins is necessary in tilapia nutrition.