Analysis of the Productivity, Immunity, and Health Performance of Nile Tilapia (Oreochromis niloticus) Broodstock-fed Dietary Fermented Extracts Sourced from Saccharomyces cerevisiae (Hilyses): A Field Trial

Abstract

The present study aimed to evaluate the effect of dietary fermented extracts sourced from <i>Saccharomyces cerevisiae</i> (nucleotides, β-glucans and MOS) (Hilyses^®) on the production and health of Nile tilapia (<i>Oreochromis niloticus</i>) broodstock, as well as on seed survival and performance. The trial was performed in a hatchery along the spawning season and continued in the laboratory to monitor the performance in fry and fingerlings. The broodstock were divided into two groups, (C) fed a basal diet and (H) fed 0.4% Hilyses. Blood and histological parameters, antioxidant power, cortisol level and the expression of some immune-related (<i>TLR-2</i>, <i>IL-1β</i> and <i>TNF-α</i>) and growth-related genes (<i>MUC-2</i> and <i>IGF-1</i>) were measured. The obtained seeds were subdivided into four treatments: (C-C) fed a basal diet, (C-H) fed 0.4% Hilyses, (H-C) fed a basal diet and (H-H) fed 0.4% Hilyses. Results revealed that the dietary inclusion of Hilyses in the broodstock increased seed production, survival, hematological parameters, and antioxidant power. Moreover, it improved the intestinal microstructure and upregulated the immune- and growth-related genes. The growth indices of fry and fingerlings were significantly increased in all Hilyses-treated groups (<i>p</i> < 0.05). The performance in the (H-H) group significantly surpassed those of all groups. Therefore, dietary fermented yeast could be used as a strategic solution to sustain tilapia production.