ABSTRACT Serum samples (n=687) from Gallus gallus domesticus were collected for the investigation of antibodies to avian influenza virus (AIV-A) in the family poultry of the surrounding counties of Santa Maria/RS and the metropolitan region of Belo Horizonte/MG, totaling twenty different counties. Additional samples of seventeen (n=17) free-flying ducks (C. moschata pure or hybrid with Anas platyrhynchos) were ...