Nucleotídeos purificados em rações para reprodutores e proles regulam a atividade de enzimas digestivas e a morfologia intestinal em tilápia-do-Nilo

Abstract

In this study, the effects of adding nucleotides to diets for broodstock and offspring of Nile tilapia (Oreochromis niloticus) were evaluated. Nile tilapia broodstock were fed diets containing 0.0, 2.5, and 5.0 g of Ascogen®/kg for five months. After this period, the eggs were collected and incubated. The offspring, at five days of age, were fed diets containing 0.0, 2.5, 5.0, and 7.5 g of Ascogen®/kg for 100 days. Analyses of digestive enzyme activity and the morphology of hepatic and intestinal tissues of juveniles were conducted. An interactive effect (p<0.05) between the diets of broodstock and offspring on trypsin activity was observed. The highest activity of this enzyme was recorded when diets containing 2.5 g/kg were used for broodstock and 7.5 g/kg for offspring. Juveniles from broodstock fed with 0.0 g/kg and offspring fed with 7.5 g/kg showed a significantly greater (p<0.05) height of enterocytes. Hepatic tissue was not influenced by the diets regarding its morphology. It is concluded that 7.5 g/kg of Ascogen® in offspring's diet promotes alterations in intestinal morphology in terms of enterocyte height. Under this condition, when associated with 2.5 g/kg of Ascogen® for broodstock, it enhances trypsin activity in the offspring.