KHER, H. N.JHALA, M. K.2018-05-232018-05-231989http://krishikosh.egranth.ac.in/handle/1/5810047305Infectious bursal disease (IBO) is considered as one of the major infections of poultry, and owes its significance by its immunosuppressive effect, which not only leads to the activation of the silent infections,but also brings about suppression of immune response to various vaccines. Present study was aimed at the seroepidemiology, pathology and immunosuppressive effect of Infectious bursal disease virus (IBDV) in poultry. Out of the 420 sera tested, 116 (27.61 per cent) were found to contain precipitins against IBDV by Agar gel diffusion test (AGDT). Seroprevalence was only found in Surat (98.05 per cent) and Baroda (19.83 per cent) districts , while Kheda and Ahmedabad districts were found to be free from the seroprevalence of IBDV at the time of the study, indicating the existence of IBD in the south Gujarat. Out of the 35 bursal samples processed by AGDT, not a single bursa tured out to possess IBDV antigen, indicating the existence of sub-clinical form of IBDV in the south Gujarat.enVETERINARY MICROBIOLOGYAN EXPERIMENTThesis