Use of the Brazil nut in the juvenile silver catfish diet and its effect on zootechnical performance and body composition

This work aimed to evaluate the effect of dietary Brazil nut (Bertholletia excelsa), on zootechnical performance of juveniles silver catfish (Rhamdia quelen). Fifty juveniles silver catfish (14.75 ± 1.42 g) were assigned to 5 treatments in a completely randomized design. The experimental treatments were different inclusion percentages of Brazil nut in the diet (T0, T3, T6, T9, T12) for 45 days. The variables final weight gain, average daily gain, protein efficiency rate, body protein deposition, body fat deposition, carcass yield and survival were evaluated. The data were submitted to analysis of variance, and the means compared by the Tukey test at 5 % significance. A lower final weight gain and a decrease in average daily gains were observed in the animals of the T3 group compared to T0. Protein efficiency rate, body protein and fat deposition, carcass yield and survival were not affected by the treatments evaluated. The inclusion of 3 % Brazil nut in the juveniles silver catfish diet, decreased the final weight gain and affected the average daily gain of the fish evaluated, without affecting the rest of the zootechnical variables studied.