Gumboro disease in semiintensive poultry farms of Dakar area

Abstract

A histological, bacteriological and parasitical survey carried out from October 1993 to May 1994 on poultry originating from 52 Gumboro outbreaks showed that the Gumboro disease prevalence was 26 and 7% in broiler and pullet farms, respectively. In 23 and 8% of the cases the disease was associated with coccidiosis and colibacillosis, respectively. A serological study revealed that disease prevalence reached 69 and 46% during the rainy and the dry season, respectively. Clinical manifestations were reported in 11% of infected broiler flocks. Vaccination against the Gumboro disease had been correctly performed in only 5% of the pullet flocks and 11% of the broiler flocks. Antibody kinetics showed that 52.6% of chicks originating from Dakar had a low protection threshold starting at week 3. However, a vaccination performed between days 9 and 12 often ensures an early and speedy seroconversion. Such high prevalence levels were due to basic hygiene rules not being followed, i.e., multiple flocks, lack of protection against diseases, poor cleaning and disinfecting, inadequate underfloor space. The use of live vaccines restored with well water to which disinfectants had often been added caused numerous vaccination failures. The Gumboro disease appears as the most common viral disease in poultry and has become a priority issue for animal health players. The first step to ensure the efficiency of control measures must be the training of farmers in hygiene practices.