Efficacy of dietary yeast cell wall supplementation on the nutrition and immune response of Nile tilapia

Prebiotics are non-digestible carbohydrates that improve the animal health via modulation of their intestinal beneficial organisms. Immunowall® is a commercial prebiotic consists of high concentration of yeast β-glucan (βG) and Mannan-oligosaccharides (MOS). The current study was designed to investigate the prebiotic potential of Immunowall® on nutrition and health performance of Nile tilapia Oreochromis niloticus. Three fish groups were nourished on control diet supplemented with 0%, 0.1% and 0.2% Immunowall® for two months. Both dietary levels of Immunowall® exhibited significant increase in growth parameters (P ≤ 0.05) as well as in white blood cell count, total protein, and globulin concentrations. While, the immune parameters such as antioxidant biomarkers (catalase and glutathione-reductase), non-specific immune response (e.g. phagocytic activity, phagocytic index and lysozyme activity) and immune-related genes expressions (e.g. TNF-α and IL-1β) were higher in 0.2% Immunowall® compared to 0.1% Immunowall® and control. Oral administration of β-glucan and MOS mixture reduced the mortalities after microbial infections with L. gravieae and A. hydrophila. Therefore, we can recommend the dietary inclusion of Immunowall® in aqua-feed as an efficient method to achieve feasible and sustainable fish production.