Immunity against viruses in chickens after applying natural and synthetic immunity stimulator.

Comparing the action of biotropin, which is a natural immunomodulator, with a synthetic one--levamisole, leads to the conclusion that biotropin acts as a strong stimulator, both of specific humoral immunity, which manifests itself in higher titres of antibodies HI and SN, and of non-specific humoral immunity, whose feature is a higher activity of lysozyme in comparison with the other groups. Similarly, biotropin increases the phagocytal activity of leucocytes, expressed as the phagocytar index and the percentage of non-phagocyting cells, more effectively than levamisole. However, the specific cell immunity, assessed by the BT and LMI tests, was slightly better stimulated by biotropin immediately after infection and by levamisole in the remaining time.