Performance of juvenile mojarra supplied with feed containing varying levels of crude protein

Abstract

The growth of the Brazilian aquaculture has stimulated the development of the productive chain of native species, including marine environment. The objective of this study was to evaluate the growth performance of juvenile mojarra fish (Diapterus rhombeus) fed diets containing different concentrations of crude protein (32, 36, 40 and 44 g 100 g -1). The 80 juvenile mojarra (7.2±1.5 g) were kept in 16 circular tanks (150 L). The study design used was completely randomized with four treatments and four repetitions. The fish were fed four times a day. At the end of the experiment (60 days) the final weight, feed intake, weight gain (WG), feed:gain ratio (FGR), protein efficiency rate (PER), energy efficiency rate, specific growth, survival rate and, body composition were evaluated. It was verified significant effect of protein level on the WG, with the best value at the level of 38.20 g 100 g -1 of crude protein. For FGR, the best estimated value occurred with 38.06 g 100 g -1 of crude protein, similar to that reported for the PER (38.91 g 100 g -1). The other performance parameters and body composition were not influenced by crude protein levels. Diet crude protein concentrations between 38.06 and 38.91 g 100 g -1 provide the best performance indices for juvenile mojarra.