Abstract: Immune effects of 4 different immune intensifiers（chicken transfer factor, astragalus, levamisole and ganoderma）were compared in this paper using Newcastle disease (ND) antibody titre as indicator. Blood samples were collected for detecting ND HI titre before experiment, ND-EDS-IB attenuated oil-emulsion vaccine was injected into each bird. And then all chickens were divided into five groups，group 1 to 4 were experimental groups and group 5 was control，and all birds were given with different immune intensifiers. Then, antibody titres of blood samples collected on 4th,6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th, 22th, 24th day post-immunization were detected by HI test, changes of HI titres were received by mathematical statistics. The results showed that HI titre of ganoderma group were significant higher than control group and other groups at 12th day firstly,and kept in high level; there were more distinct enhancement respectively in transfer factor group and astragalus group in 14th day, keeping in high level;the titre of levamisole group was higher than control group after 20th day, but there was no significant differentiation. Therefore, there were various immune efficiencies to ND vaccine with different immune intensifiers. By comprehensive consideration, chicken transfer factor (priority) and astragalus (secondary choice) would be applied in clinic, and ganoderma and levamisole should be used appropriately.

Key words: immune intensifier; immune efficiency; Newcastle disease antibody titre; chicken transfer factor; astragalus; levamisole; ganoderma