A Study on Natural Infection and Vertical Transmission of DHBV in Ducks

DHBV in duck serum is assayed by α-~(32)P-DHBV DNA probe hybridization. It is found that the rate of DHBV viremia in hybrid from Beijing duck and Cherry valley duck was 5.1％, whereas in Gauyou local ducks was32.7-58.8％.Positive sera are confirmed by EM. The virion of DHBV is characterized. Ducks are divided into four groups. The rate of DHBV viremia in tile ducklings hatched from different groups is detected, Group 1 (F~-,M~-) is 0％, Group 2(F~+, M~+)100％, Group 3(F~-, M~+)28％, and Group 4(F~+, M~-)100％. By...