Increasing levels of crude protein in practical diets for amazon prawn

Abstract

The aim of the study was to evaluate the performance of Amazon prawn, Macrobrachium amazonicum, fed practical diets containing increasing levels of crude protein. Experimental design followed a complete randomized distribution, with five treatments and six replicates. The treatments are equivalent to crude protein levels, dry matter basis, in the diet: 200, 250, 300, 350 and 400 g kg^-1. Experimental units were into a recirculation system with mechanical and biological filters to keep the water quality within the suitable range for prawn culture. At the end of the trial, mean prawn survival ranged from 84.8 to 91.3 % without significant differences among treatments (p > 0.05). Results show a quadratic growth for final weight, weight gain, final length and length growth, with the increase of crude protein levels in the diet. Prawn fed diets with 370 and 348 g kg^-1 achieved significant higher weight gain and length growth, respectively (p < 0.05). The body composition of Amazon prawns was influenced by crude protein levels in the diet, having the level of 350 g kg^-1 caused an increase in moisture content and reduction in crude protein deposition (p < 0.05), when compared to the level of 200 g kg^-1. The recommended crude protein level in the diet of M. amazonicum juveniles is 370 g kg^-1.