Digestibilidade aparente da torta de dendê na alimentação do pirarucu (Arapaima gigas Schinz, 1822) durante a fase de juvenil

Abstract

The determination of the digestibility coefficient of food is an important tool for the formulation of balanced diets, although there are few studies related to the digestibility of ingredients for pirarucu. The experiment was conducted to determine the apparent digestibility coefficient (ADC) of dry matter, crude protein, ether extract, crude energy, crude fiber and mineral material of the palm kernel cake to juvenile pirarucu. Were used twenty four animals (322, 69g) divided into two treatments and three replications containing four fish per experimental unit. The fish were distributed in 6 feeding boxes with a volume of 250L, with aeration constant and open water system circulation. The animals were fed three times a day until food satiety and at 18h, transferred to conical digestibility tanks (350 L) with a collector attached where they remained for 12 hours, the feces were processed for further laboratory analysis. A reference diet was formulated (388.1 g kg-1 of crude protein and 4336 kcal kg-1 of crude energy). The test diet consists of 70% of the reference diet and 30% of palm kernel cake. To evaluate apparent digestibility of nutrients used the indirect method of fecal collection by decantation and chromium oxide with inert indicator added to the diet at a concentration in 1 g kg-1. The values of apparent digestibility coefficients (ADC) of the diets showed no significant difference (α=0,05). ADC for the reference diets were 83,30% DM, 93,86% CP, 86,43% EE, 46,33% CF, 84,81% CE e 73,45% MM and for the test diet were of 89% DM, 96,19% CP, 91,27% EE, 78,83% CF, 89,79% CE e 88,62 MM. The mean digestibility values of the ingredient were 86,81% ± 2,70 DM; 93,91% ± 0,99 CP; 89,06%±2,98 EE; 77,46% ± 4,49 CF; 87,58% ± 2,79 CE; 71,52% ± 5,85 MM. The palm kernel cake presented high values of apparent digestibility coefficient for all evaluated nutrients indicating a potential ingredient to be increased in the feeding of pirarucu during the juvenile phase.