gholamreza Badzohreh

Introduction: For many years, antibiotics have been extensively applied in aquaculture, serving both to treat bacterial infections and to act as growth promoters. However, using antibiotics can negatively impact the environment and human health alike. For example, antibiotic use may result in the release of resistant bacterial strains into the environment, as well as the accumulation of drug residues in fish tissues. The EU has Currently banned the use of antibiotics in animal nutrition Consequently, efforts have been made to find an effective substitute for antibiotics in aquafeed. As eco-friendly alternatives to antibiotic reliance, various additives such as probiotics and postbiotics have been used for improve resistance to diseases in aquatic animals. Among different types of probiotic strains, Saccharomyces cerevisiae (yeast) and yeast fermentation products have been widely used in aquaculture since they enhance nonspecific immunity. Yeast fermentation products, as a yeast product separated from inner yeast cells, could be a functional source of nutrients. Saccharomyces cerevisiae fermentation product is a new fermented product.This product comprise rich source of nutrients that can possibly enhance the immunity and growth of fish. . Materials and methods: In this experiment, the effects of various level of Saccharomyces cerevisiae fermentation product on the growth performance, survival and some Haemato-immunological responses in juvenile Asian seabass (Lates calcarifer) were investigated. The first, 240 healthy fish with an average body weight of 9/08±0/41g were randomly were distributed to 12 polyethylene tanks with a capacity of 300 L and density of 20 fish per tank. The fish were were divided into four experimental groups in three replications and were fed with four diets as follows; control (without adding Saccharomyces cerevisiae fermentation product), FP1:0/5%, FP2:1% and FP3:2% Saccharomyces cerevisiae fermentation product. The fish were fed three time