| Popis: |
The aim of this study was to evaluate the inclusion of two commercial probiotics, a bacterial complex and a complex containing Bacillus subtilis in diets for Nile tilapia juveniles. The effects on growth performance, hematological parameters, glucose concentration, intestinal morphology and histomorphometry of hepatocytes’ nuclei were assessed. Ninety-six fish juveniles with mean initial weight of 4.87 ± 0.64 g and 6.50 ± 0.2 cm total length were randomly distributed in 12 tanks (18 L), with eight fish in each tank, during 53 days. The following treatments were designed: (C) control, (CB) feed containing the bacterial complex, and (BS) feed containing B. subtilis. No significant differences were found in relation to the growth performance of fish. In relation to the hematological parameters, a single difference was observed regarding the number of erythrocytes, with the fish treated with the diet containing the bacterial complex displayed the highest values in relation to the C and BS groups, while the other parameters were not affected by the probiotic inclusions. Similarly, no differences were observed for the proximate composition of fish. The intestinal villi of fish fed the bacterial complex (CB) were higher and wider, but the thickness of the tunic was higher in B. subtilis. The histomorphometric variables of the hepatocytes’ nuclei of the fish from the CB treatment revealed higher values of area (μm²), perimeter (μm) and volume (μm3). It was concluded that there are no significant differences between the application of a bacterial complex or B. subtilis as probiotic additives for Nile tilapia juveniles. |
