1969 Volume 22 Issue 12 Pages 606-611
A total of 1, 771 serum samples were collected from cattle allowed to graze in 38 pastures in 1967 and examined for the presence or absence of hemagglutination-inhibiting antibody against bovine adenovirus type 6. Of them, 51.8 per cent was positive for antibody.
Antibody-positive sera were found in 47.4, 53.9, and 51.9 per cent of the sera collected in the early, middle, and late stage of grazing, respectively. The positive rate was the highest, or 100 per cent, in a pasture of Aomori Prefecture in the late stage of grazing and the lowest, or 5.3 per cent, in a pasture of Oita Prefecture in the late stage of grazing.
Of 566 cattle surveyed, 157 showed an antibody titer of 1: 4 or higher after they were allowed to graze. These cattle were presumed to have been infected with the virus immediately before or after grazing.
It was serologically demonstrated that the infection of this virus had been spread all over the country.