Rice bran in the diet as an enriching source of long chain Omega (n-3) poly unsaturated fatty acids (LC n-3 PUFAs) in fillets of genetically improved farmed Tilapia (GIFT)

Abstract

Rice bran is a cheap, easily available, widely used fish feed ingredient in Asian countries. In this study, contribution of rice bran on the growth and fatty acid profile of fillets of genetically improved farmed Tilapia (GIFT) fish was evaluated. Two diets with 30 % protein and different lipid levels (7.70 % in Diet I and 12.55 % in Diet II) were formulated. Diet I had 9 % rice bran and 18 % maize whereas Diet II had 24 % rice bran and 3 % maize. Other ingredients were common and used in same percentages. GIFT fingerlings were randomly stocked in 8 cages (quadruplicate/treatment) at a density of 75 fingerlings/ m 3 and fed with the two test diets for 210 days. Growth performances were recorded monthly. At the end of the experiment proximate composition and fatty acid profile of GIFT fillets were determined. Crude protein and crude lipid percentages were higher in fillets of fish fed with Diet II. Total poly unsaturated fatty acids (PUFAs), total omega (n-3) fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid in fish fed with Diet II were higher and significantly different from the fish fed with Diet I (p = 0.00). Mono unsaturated fatty acids were significantly low (p = 0.00) in fish fed with Diet II. No significant difference was observed in mean final weight, specific growth rate, feed conversion ratio, protein efficiency ratio or survival rate in fish fed with the two diets revealing that incorporation of rice bran into the diet at a higher percentage could improve the nutritive quality of GIFT fillets while maintaining the growth and survival.