Novos prebióticos na nutrição de tilápia do Nilo

Abstract

The study was conducted in order to develop new prebiotic obtained from the orange peel and linseed grain, and evaluate the effects of supplementation in the diet of Nile tilapia (Oreochromis niloticus). During 60 days, 720 Nile tilapia (average weight: 3.4 ± 0.60 g) were maintained in 24 polypropylene boxes with a volume of 280 liters (30 fish / tank) arranged in a water recirculation system. Fish were fed three times a day with the experimental diets with addition 2.5 and 5 g kg-1 of ORANPre, LINPre and Actigen (commercial prebiotic). The design was completely randomized in a 3x2 factorial arrangement, a total of six treatments with four replications. The water quality was monitored regularly, keeping within the ideal for the development of species. At the end of the trial period, were evaluated the growth parameters, carcass parameters, digestive indices, hematological and metabolic parameters. The extraction yield of new prebiotics was 16.8% for ORANPre and 7.8% for LINPre, both extracted in middle-aqueous. The hydration capacity (HC) and fat binding capacity (FBC) were higher to LINPre, but the added levels did not change the HC and the FBC of the diets. It was observed a higher final weight of the tilapias fed diets containing non-commercial prebiotics (ORANPre and LINPre) and independent of the prebiotic, the best results in the final weight and length were observed for 2.5 g kg-1 of inclusion. Prebiotics showed equivalence as its action on the specific growth rate, carcass yield, total biomass, relative weight gain, feed conversion, survival, hepatossomatic index and visceral fat index. The digestive somatic index was higher for the diet with inclusion of ORANPre did not differ from diet with inclusion of Actigen. There was a higher body protein deposition in tilapia fed with diets containing ORANPre, not differing from those with inclusion of LINPre. The total fat deposited was higher for the lowest level of inclusion (2.5 g kg-1 ). Hematological parameters were not influenced by prebiotics and inclusion levels. In the metabolic parameters were observed higher concentrations of liver glycogen in the diets with inclusion of ORANPre and Actigen, with no difference between the levels tested. For body moisture was observed interaction (P<0.05), where the animals fed diets added 5 g kg-1 of Actigen showed higher moisture retention. The results demonstrate that the non-commercial prebiotics ORANPre and LINPre are equivalent or superior to commercial prebiotic (Actigen), indicating the possibility of using these new prebiotics in the Nile tilapia diets.