Optimization of Dietary Protein Requirement for the Growth, Survival and Feed Utilization of Osteobrama belangeri (Valenciennes, 1844) Fingerling

In order to optimize dietary protein requirement of Osteobrama belangeri fingerling an experiment was conducted by using six semi-purified diets with graded protein levels (20, 25, 30, 35, 40 and 45%) using casein and gelatin as main protein source. Six treatments in triplicates (18 circular fiber reinforced plastics tanks; 1000 l capacity each) were used to conduct the experiment for 75 days in the wet laboratory. Ten fingerlings with mean body weight of 4.23±0.08g were stocked in each tank and fed twice daily. The mean weight gain and specific growth rate was recorded highest in fish fed with 25% protein diet. Similarly, net biomass gain, body weight gain and daily weight gain was highest in fish fed with 25% protein diet. 30% and 35% protein diets gave 100% fish survival. The lowest feed conversion ratio (FCR) and highest feed conversion efficiency (FCE) was also recorded in 25% protein diet. Moisture, crude protein, crude lipid, crude ash contents of O. belangeri did not differ significantly among the treatments. Thus, growth performance and feed utilization was optimum in fingerling of O. belangeri while they were fed semi-purified diet containing 25% protein.