Two trial experiments were conducted to determine a reference diet for nutrient requirement studies of Piaractus brachypomus. In the 1st experiment four diets elaborated with purified ingredients (H-440 with 47% PB, C-102 with 41% PB, NRC, with 37% PB and IALL-1 with 32% of PB) and a diet control (32% of PB) with common ingredients, were tested. In the 2nd experiment the diet IALL-1 was used as base for the formulation of three experimental diets. Diet 2 contained vitamin C and macrominerals premix supplement, while in diet 3 vegetable oil was substituted by fish oil. Weight gain, taking also into account the relative food intake, specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER), protein retention (%PPV) and energy retention (%RE), was used as the basic approach for measuring the effects of the diets. The best growth performance and nutrient use among semipurified diets was observed for diets NRC and IALL-1. In the 2nd experiment, fish fed diet 2 presented a growth (42%) greater than those fed non supplemented diets. Other analyzed variables FCR, SGR, PER and %PPV were also significantly improved. The added results indicate that macro minerals and vitamin C supplemented- diet IALL-1 can be effectively used as a reference diet for nutrition studies on juvenile P. brachypomus.
Piaractus brachypomus; reference diet; fish nutrition; fresh water fish; pirapitinga; Piaractus brachypomus
