Performance of Brewer’s Yeast as a Sustainable Fishmeal Alternative in Labeo rohita Nutrition: Effects on Growth, Hematological, Enzyme Activities and Biochemical Indices

Abstract

Members of the carp family are among the most significant inland aquaculture species worldwide. Rohu and grass carp hold considerable importance in regions of Asia. Nutritional composition of fishes depends upon nutritional values of meal provided to them. For this purpose, aquafeeds industries are trying to prepare complete meal for favorable nutrition. Five experimental diets names as D1, D2, D3, D4 and D5 were prepared in laboratory by replacing 15, 30, 45, 60 and 100% fishmeal by brewer’s yeast respectively. Rohu fingerlings were fed with controlled diet for acclimatization for 15 days before starting trials. After acclimatization 30 fingerlings were randomly distributed in each tank. Data was recorded for various growth, hematological, biochemical and digestive enzymes activity attributes. D2 and D3 provided significant results for all growth attributes. D2 caused 27, 34, 14 and 6% increase in final weight, weight gain, specific growth rate (SGR) and survival as compared to fingerlings fed with controlled diet. Red blood cells (RBC) of fishes fed with D2 and D3 were 36% higher than fishes fed with controlled diet. While white blood cells (WBC) highest value was observed in rohu fed with D5. Hemoglobin content was also found highest in fishes fed with D2, which were 16.3% higher than fishes fed with controlled diet. Unlike growth and hematological attributes, biochemical attributes such as glucose, cortisol, alanine amino transferase (ALT) and alkaline phosphatase (ALKP) were significantly reduced in fishes fed with D2 and D3 experimental
diet. D4 and D5 caused significant increase in the biochemical attributes. Highest activity of protease and lipase was also observed under D2 diet. From these results, it can be derived that fishmeal 30- 45% replacement with brewer’s yeast can become a good sustainable alternative diet for Labeo rohita culture.