Comparative Clinicopathological Studies on Some Immunosuppressors And Immunostimulants In Gumboro Disease In Chickens

In this work we tried to evaluate the immunogenic effect of aliveintermediate IBOV vaccine applied at early age ( 1 day) and repeatedat 11 and 21 days . Also we studied the effect of immunostimulantswhen administered following each vaccination for 3 successive days.Levamisole, vitamin E witih selenium and Nigella sativa extractsshowed variable degrees of immunostimulation which encourage theidea of their use after each vaccinatioa but we observed that Nigellasativa ethanol and acetone extracts showed a hepatotoxic effect whilechloroform and ethanol aquous extracts showed no hepatotoxic effect .Stimutation index and both gamma-globulin and antibody titersall showed that ethanol aqous extract is the most acceptable extract tobe used for immunostimulation without any undesired side effect.Both levamisole and vitamin E when used after each vaccinationshowed an important degree of cellular and humeral immunityimprovement as indicated by increased gamma-globulin and antibodyresponse and also stimulation index.One day vaccination showed a good result on challenge withIBOV inspite of presence of mild symptoms of IBOV on the challengedchickens, but these symptoms were not found when levamisole, vitaminE and Nigella extracts were used .