[Results of a serological survey made in France (Vendeé region) in domestic ducks].

The sera of domestic ducks were examined for antibodies to several infectious agents of palmipeds during the winter of 1982 in the abattoirs in la Vendée, an important region of duck production in the West of France. The performance of each batch and their antecedents was also studied. In Barbary ducks and crossbred ducks (from male wild ducks and female domestic ducks), antibodies were found to the virus of egg drop syndrome 16 (EDS 76), to Newcastle disease virus (NDV), to duck hepatitis virus and to chlamydia psittici. In Nantais ducks (resulting from a cross between Khaki Campbell and Pekin ducks), antibodies were detected against EDS 76 virus, duck hepatitis virus and chlamydia. The frequency and levels of antibodies varied between types or strains of ducks. About 50% of the Barbary ducks had high levels of antibodies to EDS 76 virus, whereas 70 to 80% of crossbred and Nantais ducks had these antibodies but at very low levels. Virtually 100% of Barbary ducks had high levels of antibodies against Derzsy's disease virus whereas only 10% of the batches of crossbred ducks had antibodies at varying levels. The proportion of batches with antibodies against NDV was higher in crossbred ducks (25%) than in Barbary ducks (2%) and the titres were low. Antibodies to duck hepatitis virus, when present, were of a high titre irrespective of type or strain of duck. Infection by chlamydia was suspected in 3% of lots of Barbary ducks, in 33% of lots of crossbred ducks, and in 3.7% of lots of Nantais ducks. These findings are discussed and considered in relation to breeding history and performance of the flocks. The EDS 76 virus could in certain circumstances cause weight loss in male Barbary ducks. These epidemiological observations need to be confirmed experimentally.