Antibodies against avian viruses in backyard poultry from the Rio Grande do Sul State, Brazil

The backyard poultry are not included in the biosecurity system applied in commercial flocks in Brazil. To investigate the presence of antibodies to specific viral pathogens in this population, blood samples were collected from 867 non-vaccinated birds, from 60 flocks in 22 counties of the Rio Grande do Sul State, Brazil. The samples were tested to detect antibodies against infectious bronchitis virus (IBV), avian reovirus (ARV) and infectious bursal disease virus (IBDV), through the virus neutralization test. Antibodies to IBV were detected in 65% (564/867), against ARV in 21.6% (187/867), and against IBDV in 80.2% (695/867) of the samples. All the flocks had chickens positive to IBV and IBDV antibodies, and 88.3% of them harbored antibodies to ARV The results show the presence of these viruses in backyard poultry from the central region of the State. It also indicates the need for additional studies aimed to evaluate