Immunostimulatory effect of mannan-oligosaccharides supplementation diet in milkfish (Chanos chanos)

The current study was designed to examine the impacts of dietary mannan-oligosaccharides (MOS) on growth, hemato-biochemical changes, digestive-antioxidant enzyme activity, immune response, and disease resistance of milkfish (Chanos chanos) fed diets contained MOS i.e. 1g, 2g, and 3g MOS. The growth parameters were significantly influence in milkfish fed all MOS diets, whereas the feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly influence with 2g or 3g MOS diets. The total protein (TP), globulin (GB), and glucose (GLU) levels, amylase, protease, liver enzymes were found significantly high in fish fed 2g or 3g MOS diets; but, lipase, trypsin, and alkaline phosphatase (ALP) enzymes were increased significantly at 3g MOS diet. All MOS inclusion levels were significantly increased total and Lactobacillus intestinal microflora population. The oxidative enzymes activity as superoxide desmutase (SOD) and catalyze (CAT) were progressively increased with all MOS supplementation diet, but the glutathione peroxidase (GPx) and lactate dehydrogenase (LDH) content were found significantly high in fish fed 2g or 3g MOS diets. Similarly, the reduced glutathione (GSH) and glutathione reductase (GR) contents were observed significantly high level in fish fed 3g MOS diet. The phagocytic (PC) and lysozyme (LYZ) activities were found gradually increase in fish fed increasing level of MOS diets, while the respiratory burst (RB) and malondialdehyde (MDA) activities were seen significant in fish fed 2g and 3g MOS diets. The current research work confirmed that C. chanos fed diets contained 3g kg^-1 MOS recorded better growth performance, digestive-antioxidant, immune response, and disease resistance.