The increase in populating, the demand for aquaculture and the limitation of water resources have caused compressed breeding in the aquaculture industry, which is directly related to the spread of the disease and the use of antibiotics for treatment. Considering the side effects of antibiotics, the use of immune stimulants that increases resistance to environmental stresses and infectious diseases is very important in this industry. The present study was conducted with the aim of investigating the ability of killed (with formalin) bacteria of the genus Vibrio (V.harveyi, V.alginolyticus, V.parahaemolyticus) on the immunogenicity of Asian seabass (Lates calcarifer). For vaccination in injection treatment, 250 microliters of polyvalan antigen was injected on day 1 of the experiment (treatment 1) and Also, in another treatment with similar conditions, 250 microliters of polyvalent antigen was injected with 250 microliters of injectable glucan (final concentration of glucan 1 mg/250 microliters) (treatment 2). Oral vaccination with alginate/chitosan/alginate microcapsules was performed on day 1 after the adaptation period (for 10 days) (treatment 3). Also, in another treatment with similar conditions, yeast-based glucan adjuvant was used (treatment 4). in which 15% glucan supplement was added to fish food at the rate of 7 g/kg (final glucan concentration 1 mg/g) and immune enhancement was done on the 30th day of the experiment. On day 60, a bacterial challenge test was performed. 3 control groups fed with food pellets (control 1), fed with food pellets and glucan injection (control 2) and fed with food pellets along with oral glucan were considered. The safety of fish blood serum was checked on the 15th, 45th and 70th day And according to that, the activity of lysozyme, complement and the amount of total immunoglobulin and immunoglobulin M were investigated.
And on the 15th and 45th days, treatment 4 had the best result in all the investigated factors, and control 1 had