Dietary supplementation of microbial phytase improves growth and protein efficiency ratio of freshwater prawn ( Macrobrachium rosenbergii )

Phytase is a phosphatase enzyme involved in catalyzing the hydrolysis of phytic acid, which is abundant in plant-derived ingredients that are known to be best alternatives for expensive and scarce fish meal in aquafeeds. In this study, the effect of dietary supplementation of microbial phytase at 250, 500, and 750 FTU/Kg on growth, survival and body composition of freshwater prawn ( Macrobrachium rosenbergii ) was investigated. The growth and protein efficiency ratio in phytase-incorporated diet-fed prawns were significantly increased when compared to the phytase-free diet-fed prawns. The diet supplemented with 250 FTU microbial phytase-fed prawns showed best growth of 50.84 g in terms of mean weight, compared with the phytase-free diet-fed prawns showing 27.88 g in 90 days trial. In addition, a highest protein efficiency ratio of 2.12 was found in 250 FTU phytase-incorporated-diet-fed prawns, compared with 1.53 in phytase-free diet-fed prawns. Furthermore, there was no significant difference in the survival of prawns fed with phytase-supplemented and phytase-free diets. These results indicate that the dietary supplementation of microbial phytase in prawn diet would be beneficial in better utilization of plant-derived feed ingredients, which are of most promising alternatives to expensive and scarce fish meal in aqua feed formulation.