Incidence of Gumboro-Disease Among chickens in Upper Egypt

ThG degree of exposure of chicken fl oc ks to inf ec- tious bursal disease virus (IBDV) at different 10-c oLi. ties Ln Assiut and El-yvo.di El-Go.did Governor- ates were studied serologically and virologically.2. 31.59% of the examined serum samples from breeding flocks ahowed precipi ti.l1s to IBDV. 3. 40% of the negative serwn samples in the AGP test showed neutralizing o.ntibodies.Out of 440 Wltreated yolk samples exo.mined by the j~GP test. 53 (12.04%) were positive. Treatment ofyolk with chloroform help the detection of undetec-table precipitins by the LGP test (17.27%). 5. Day-.old chicks from B.eni-1Jur paul try farm poss eSG edprecipitating and neutrcLlizing cJltibodies to lBD viruswhich protected 20% of them up to 2 weeks of Gge. 6. 12 is 010. tes IBDV were recovered from 563 moribundand uGad, 3 - 9-woek-old chicks.Two isolntes Vlere subjected to physical chcmi cu.L, serologiccl, und biological characterization.