| prevalence of bovine parvovirus infection in ontario dairy cattle. | studies were conducted to determine prevalence and dynamics of bovine parvovirus (bpv) infection. dairy cows from 29 randomly selected herds in southwestern ontario were tested twice, one year apart, for the presence of hemagglutination inhibition (hi) antibodies against bpv. fifty-one percent of 1141 cows tested had bpv-hi titers > 1:32. one year later, the seroprevalence was 83% in 1131 cows from the same farms. the herd mean seroprevalence was 49% and 86% for the year-1 and year-2 samples, re ... | 1995 | 7648531 |