Demanda protéica de juvenis de tambaqui (Colossoma macropomum) após privação alimentar

Abstract

This study evaluated the effect of energy/protein ratios in the performance, corporal composition and hyperphagia duration of tambaqui juveniles (Colossoma macropomum), after feed privation. Using a complete randomized design, 384 juvenile with average weight and standard deviation of 50,32 ± 0,26g were distributed in 24 tanks of 310L and draftes among eight treatments with three repetitions each. A factorial project was adopted (4x2), resulting from the combination of four isocaloric fish feed with different concentrations of proteins (28,0%, 32,0%, 36,0% and 40,0% CP) and two feeding regimemts (with privation and without privation). Half of the fish were submitted to a period of privation of 14 days followed by 46 days of re-feeding and the remaining fish were fed during ther whole experiment. The zootechnical performance of the fish was evaluated in both experimental periods. At the end of the privation period there was a reduction in the growth rate and weight of the fish under the restriction regime and an increase of those parameters in the feeding regime supplied with the different feed. In the re-feeding period hyperphagia was also evaluated and the feed with 36,0% CP, 3.407 Kcal/Kg digestible energy/crude protein of 9,5:1 was the most efficient, because the fish reached the best productive performance in terms of feed efficiency, profit of relative weight, specific growth rate and longer hyperphagic feeding duration. The different energy/protein ratios of the feed compensated the weight gain of the fish of the restriction regime, which reached the medium weight of 102,05g at the end of the experiment, similar to the fish continually fed. The corporal composition of the fish was evaluated at the end of the experiment with the highest deposition of corporal protein and fat on fish submitted to the restriction regime when fed with 36,0 % CP feed. Therefore, this study showed that juvenile of tambaqui do not increase their demands for protein to support the largest growth during the compensation of the weight profit.