The use of a probiotic Saccharomyces cereviciae to reduce mortality in Oncorhynchus mykiss fry

Abstract

A preliminary trial was conducted to evaluate the survival of trout fingerlings (Oncorhynchus mikyss) fed a diet with different levels of yeast (Saccharomyces cerevisiae) inclusion. The trial was conducted in an open-circuit system located at the La Esperanza Fish Farm, Ibarra canton. The fingerlings were fed a commercial feed (50% protein, 15% lipids), to which 1, 2, and 3% yeast were added, and the control diet without any additions. 240 fingerlings with an initial average weight of 5.87 ± 1.89 g were randomly distributed within 12 cages with a capacity of 62.5 L. During the experimental phase, the average water temperature was 11.93 ± 0.97 ° C; oxygen 8.45 ± 5.22 mg / L; electrical conductivity 76.09 μm/cm and pH: 8.53 ± 0.45. The experiment lasted 16 days. At the end of the experiment, there were no statistically significant differences in the mortality rate, growth parameters, or nutritional efficiency. Furthermore, in the evaluation of biometrics, statistically significant differences were only observed in the intestinal index between fish that consumed 1% brewer's yeast compared to the control diet. It was concluded that the addition of brewer's yeast did not significantly improve the survival of trout fry.