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

Abstract

Optimization of dietary protein for fingerling of Osteobrama belangeri was carried out using six semi-purified diets with graded levels of protein (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 of each tank) were used for conducting the experiment for 75 days in the wet laboratory. Ten fingerlings with mean weight of 4.23±0.08g were stocked in each tank and fed twice daily. The mean weight gain and specific growth rate was highest in the fish fed group with 25%protein in the diet. Similarly, net biomass gain, body weight gain and daily weight gain was higher in fish fed with 25% protein level. 30% and 35% protein diets gave 100% fish survival. Lowest feed conversion ratio and highest conversion efficiency was found in 25% protein. Final moisture, crude protein, crude lipid, crude ash contents of O. belangeri did not differ significantly within the treatments. Therefore, the optimum value using broken line regression was recorded for specific growth rate at 24.63% protein for fingerling of O. belangeri on growth performance and feed utilization using semi-purified diet.