Abstract

Yan QIU *, Yuan-Liang HU , Fa-Ming DONG , De-Yun WANG and Zhan-Qin ZHAO

This study was conducted to evaluate the effects of three Chinese herbal crude polysaccharides on immunoglobulin A secreting cells and serum antibody titers in vaccinated chickens. A total of 450 14-day-old chickens were randomly assigned to nine equal groups and all chickens were vaccinated. Concurrent with the first vaccination, chickens in groups 1 to 8 were intramuscularly injected with four crude polysaccharides among which the astragalus polysaccharide (APS) was selected as positive control at high and low doses, and group 9 (control group) with saline once a day for three successive days. The numbers of positive immunoglobulin A (IgA) secreting cells and the serum specific immunoglobulin G (IgG) antibody were determined by immunohistochemistry and micro method. The results showed that the individual administration of any of the three crude polysaccharides could significantly increase the number of IgA secreting cells, and the maximum numbers of increased IgA secreting cells in the cecum tonsil and duodenum in the three polysaccharides groups were 37.7 and 33.5 when compared with the controls, and those of the APS groups were 33.9 and 32.7. These three crude polysaccharides at appropriate doses also significantly enhance anti-Newcastle disease virus antibody titers, and the maximum antibody titer increase in the three polysaccharides groups was 1.6 log2 when compared with the control group, and those of the APS groups was 1.7 log2. These findings indicated that the appropriate doses of the three crude polysaccharides possess significant immune enhancing properties of mucosa and humoral immune response s, which have similar effect with astragalus polysaccharide, and may be useful as a new type of immune potentiator during vaccination