Effect of Different Levels of Protein on Growth Indices, Feed Efficiency and Body Composition of Cultured Juvenile Beluga (Huso huso Linnaeus, 1754)

The effect of different levels of protein on the growth performance of juvenile Beluga was studied using five semi – purified, isolipid (11.5 ± 0.71%) diets containing 20, 25, 30, 35 and 40 % protein (D1 to D5). This experiment was conducted for 8 weeks duration in order to ascertain the optimum level of protein requirements for experimental juvenile Beluga (40 ± 2.29g). Two – hundred and twenty five fishes were randomly distributed between 500L fiberglass tanks, filled with 400L of freshwater. Fish performance in the terms of WG, SGR, FCR and survival rate were best and significantly different(P<0.05) at 35 and 40% protein levels (D4 and D5). However, protein efficiency ratio (PER) was best in the diet D4 with 35% protein level. Growth performance was poor in D1 and D2 at 20 and 25% protein levels (P<0.05). Body composition improved with increasing protein levels. In diets D3, D4 and D5 significantly (P<0.05) higher protein and lipid deposition with lower moisture and ash content were observed. This study indicated that a minimum level of 35% protein is required for optimum growth in Beluga.