Optimization of Energy to Protein Ratio in Feed for Labeo rohita Fingerlings

Abstract

Ten semi-purified diets with two levels of dietary protein (32 and 41%) having five energy levels each (324, 341, 364, 384 and 407 kcal.lOOg1) were formulated and fed to Labeo rohita fingerlings for a period of 45 days. Factorial analysis of variance indicated that although weight gain, food conversion efficiency and protein utilization were significantly affected by dietary energy and protein levels, the energy and protein conversion efficiencies were not influenced by dietary energy and protein interaction. The best growth and food conversion ratio (FCR) were obtained with an average of 379.72 kcal.lOOg1 at 41% protein diet (P/E 107.87 and E/P 9.29), while maximum protein utilization and conversion occurred with similar energy levels (383 kcal.lOOg"1) but in low protein (32%) diet. Although dietary energy influenced the body constituents of fish, the influence of protein was not significant. The results indicated that with increased allowance of energy, more protein was utilized for tissue building and enhancement of growth. Key words: Protein-energy ratio, optimum