Chickens rising have long been a line of tradition and the large numbers of chicken populations are kept in the backyard production system in Ethiopia. Poultry disease is among the main constraints of poultry production in the country. The infectious bursal disease is widespread viral diseases that affect chicken kept in commercial and backyard production system. Infectious bursal disease virus is a primary affect bursa fabricia of young chicken and is host-specific. This virus is prone to

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... ion, extremely stable and unaffected by chemicals and disinfectant. The most common route of infection is oral, conjunctiva and respiratory. The infectious bursal disease is extremely contagious and its severity is depends on age, breed of the affected birds, the degree of passive immunity and the virulence of the strain of the virus, and secondary infections associated with the immunosuppressive effects of the disease. Control of the disease has been more difficult by the popularity of variant strains of the infectious bursal disease virus. Variant viruses induce damage within the bursa fabricia in chickens, even once high and uniform protein titers are presence. The infectious bursal disease has an enormous economic impact on production varying from direct to indirect losses. Direct losses of disease are due to mortality and the financial losses due to reduced production parameters as a result of subclinical infections. The indirect economic impact of the disease is immunological disorder, growth retardation and condemnation of carcasses. With proper use of vaccine and vaccination program together with other measures like sanitation, good nutrient, high level of management in poultry farms was suggested.