Farelos de arroz desfitinizados na nutrição de jundiá (Rhamdia quelen)

Abstract

This survey was conducted for the purpose of evaluating the performance, metabolism, bone mineral deposition and phosphorus excretion in feces of Rhamdia quelen juvenile fed with defatted rice bran which phytic acid was extracted or degraded. The experiments for evaluating the performance and metabolism and fecal collection were conducted in recirculating water system with controlled temperature. The first trial for 60 days, we evaluated the performance of 300 juvenile catfishes (13.36 ± 1.20 g) fed four experimental diets were isonitrogenous and isocaloric, which formed the treatments: CONT - comprised of conventional ingredients; FADE - with 20% defatted rice bran; FADFIT - with 20% defatted rice bran treated with 1500 FTU phytase / kg of bran; FADEX - with 20% defatted rice bran with phytic acid extracted in a randomized design with three replicates per treatment. In the second experiment, the fecal collection was conducted by Guelph system, using 240 silver catfish juveniles (52.15 ± 8.42 g) placed in incubators (200L) with stopcock and falcon tubes at the bottom, lasting 17 days. No significant difference in growth and composition of whole fish, except for body fat was higher in the catfishes fed with FADEX that FADFIT. With respect to metabolism, it was found that CONT diet provides low glycogen stores and that FADE and FADFIT diets caused higher mobilization of these body reserves compared to FADEX. Increased deposition of phosphorus was found in the bones of fishes fed with FADEX. However, dephytinized rice brans did not influence the excretion of this mineral. Under the conditions of this research, we conclude that the degradation or extraction of phytic acid did not affect growth, although modifying the metabolism. The use of dicalcium phosphate, due to the extraction of phytic acid, promoted higher deposition of phosphorus in the bones of the catfishes, but did not influence the mineral excretion via feces.