Combined Effect of Papain and Vitamin-C Levels on Growth Performance of Freshwater Giant Prawn, Macrobrachium rosenbergii

摘要

Present study was conducted to evaluate the combined effect of proteolytic enzyme, papain and vitamin-C on freshwater giant prawn, Macrobrachium rosenbergii. Post-larvae of Macrobrachium rosenbergii of average weight 9.5-16.3 mg initial weight were fed with eight different diets supplemented with papain 0.0%, 0.108%, 0.3%, 0.5%, 0.0%, 0.108%, 0.3%, 0.5% and vitamin-C 0.0%, 0.0%, 0.0%, 0.0%, 0.2%, 0.2%, 0.2% and 0.2% for feeds F1 to F8 respectively. Before the start of the experiment, prawns were reared using papain and vitamin-C free diet in order to deplete their vitamin-C stores. The same diet formulation was used in all treatments containing soybean meal, fish meal, shrimp meal and wheat flour as the major ingredients. Feeding level was kept same for all the groups of prawn and fed to satiation. Protease specific activity after one hour of feeding at the end of the experiment was estimated, which have shown a higher value in comparison to the protease specific activity one hour before feeding at the beginning of the experiment. The results obtained after feeding trial demonstrated improved growth (P<0.05) at higher concentration (F7 and F8). However, the growth of post-larval stages of prawn fed only vitamin-C or papain showed lesser growth than those of the combined effect. Survival was recorded between 46-56% in all the treatments. No growth reduction or deficiency signs were observed. This finding is the first report of its kind where a combined effect of papain and vitamin-C showing a synergistic effect on the growth performance. Further standardization and commercialization of this finding, through economically viable methods, is needed to improve the growth performance of this premium commodity.