Some studies on the effect of bce on tick-borne protozoal parasites of cattle

The present study was carried out to investiga~e on the effect of BCG vaccine on tick-borne protozoal parasites;Babesiaand Theileria species in cattle. Two trials were carried out: a laboratory controlled trial 10 the Animal Health Research Institute, and a field trial in a governmental farm at Beni Swef.The first trial was carried out on 5 cross-Friezian calves to study the effect of liD injection of BCG vaccine on both Babesia and Theileria spp.The results showed that the dosage of BCG given has stimulated a resistance in the calves against infection with Babesia bigemina. Also these results revealed that the spleen had played an important role in the production of such resistance.The interval between injection with BCG vaccine and infection with ~. bigeminato allow the development of the immunizing effect of the vaccine, must be not less than 28 days. In this experiment, it has been found that liD injection of BCG has no effect onThe second trial was under taken in the field on 49 calves, to study the effect of BCG vaccine injected either intradermally or subcutaneously on ~. bigeminaand T. annulata. For comparison, Imizol was tried as a drug um sample to study compratively the efficacy of each in detectingpullorum carriers.a. While the rapid slide serum agglutination gave the highest pos-itive percentage (47%), it had also a high ratio of non specificreactions.b.Indirect haemagglutination test gave 37% positive results butit had the advantages in saving time, costand materials.b.Agar gel pericipitation test gave ’only 17% positive results wh-ile it has a highefficacy in detecting early infection.b.Micro agglutination test gave 12% and this lowering in positiveresults is due to the very low agglutinin titerswhile the resultinterpereted as positive must not less than 1/40.Two groups of chickens were infected with salmonella gallina-rum-pullorum variant and standard serotype (5xl07) viable organism.