Sorgo em dietas para juvenis de Rhamdia quelen suplementadas com fitase

Abstract

The present study aimed to evaluate the productive performance of silver catfish juveniles fed with diets containing different sorghum inclusion levels as a substitute of maize, and supplemented or not with the phytase enzyme. The diets were composed of maize, maize/sorghum and sorghum, supplemented or not with phytase enzyme (1500 UFA/kg-1). Apparent feed conversion and specific growth rate were better for supplemented diets (P<0.05). The larger protein efficiency rate was obtained for maize diet supplemented (P<0.05). The viscerosomal fat index was lower when maize/sorghum diet was used (P<0.05), whereas the hepatosomatic index was smaller for maize and maize/sorghum diets, regardless of supplementation (P <0.05). The plasmatic biochemical components presented variation (P <0.05), but they remained within the limits of the species. The histomorphometric variables presented variations for sorghum and sorghum/maize diets, supplemented or not (P<0.05). The chemical composition of the carcass presented variations related to ethereal extract and mineral matter deposition for supplemented diets (P<0.05). In bone mineralization there was a variation of Ca (P<0.05) when maize and sorghum were used in the same proportion. Therefore, sorghum may be a viable alternative to maize substitution, and phytase supplementation improves the productive performance of fish.