Abstract
To determine the effect of astragalus and ginseng polysaccharides (APS, GPS) on immune response and improvement of H5N1 vaccine, 360-day-old broilers were randomly divided into 8 groups of 45 chicks, comprising APS groups (1-3); GPS groups (4-6); vaccine group (7); and blank control (8) (without polysaccharide and vaccine). From day 12 after hatch groups 1-3 were given APS and groups 4-6 with GPS both at 100, 200, and 400 (mg/kg), respectively. At day 15 after hatch, groups 1-7 were vaccinated with 0.3 mL H5N1 vaccine subcutaneously; daily weight gain (DWG) and serum Ig antibody (by HI-test) were measured on 3, 7, 14, and 28 days after vaccination. Serum antibody titers and expression of cytokines (IL-2, IL-10, I FN-γ, and TNF) were determined by ELISA and RT-PCR. Results revealed that all the polysaccharide groups were numerically increased in antibody levels and the expression of cytokines was significant (P < 0.05) in the APS and GPS groups compared to corresponding vaccine group and blank control. DWG was higher (P < 0.05) in 400 mg/kg APS groups than control groups. Thus oral supplements of GPS and APS have shown their potential in the improvement of immune response and could be used as adjuvant in a formulation of H5N1 vaccine.