The Effects of Fermentable Dietary Fiber on Performance and Metabolism of Nile Tilapia (Oreochromis niloticus)

This study was conducted to evaluate the inclusion of new prebiotics in the diet on performance and metabolism (liver protein, glucose and glycogen) of Nile tilapia. For 60 days, 720 Nile tilapia (3.4 +/- 0.60 g) were maintained in 24 polypropylene tanks (280 liters). Fish were fed with experimental diets with addition of 2.5 and 5 g kg(-1) of dietary fiber of citrus pulp (DFCP), dietary fiber of linseed (DFL) and Actigen (R). The experimental design was completely randomized with a 3x2 factorial arrangement. At the end of the period, there was higher final weight of tilapias fed on diets containing DFCP and DFL, and regardless of prebiotic, the best results in the final weight and length were observed for inclusion of 2.5 g kg(-1). There was higher body protein deposition in tilapia fed on diets containing DFCP, without differences from those with inclusion of DFL. Total fat deposition was higher for the lowest level of inclusion (2.5 g kg(-1)). The digestive somatic index was higher for the diet with inclusion of DFCP, which did not differ from the diet with inclusion of Actigen (R). There were higher concentrations of liver glycogen in the diets containing DFCP and Actigen (R). Faced with the search for alternative growth promoters, this study confirms the possibility of using the new prebiotics (DFCP and DFL) in nutrition of Nile tilapia, because they showed efficiency equivalent to the prebiotic Actigen (R).