Publications

control of bovine leukemia virus infection in dairy herds by agar gel immunodiffusion test and segregation of reactors.	canadian cattle intended for export, in future, may have to originate from herds which are serologically negative for bovine leukemia virus, in addition to being negative individually by the agar gel immunodiffusion test as currently required. in this study, agar gel immunodiffusion testing of herds and segregation of reactors were examined. the results demonstrated that bovine leukemia virus infection could be controlled when three groups: 1) bovine leukemia virus-positive, 2) bovine leukemia v ...	1989	2536579
a serological survey for bovine immunodeficiency-like virus in ontario dairy cattle and associations between test results, production records and management practices.	a chemiluminescence western blot analysis (wba) for detecting antibovine immunodeficiency-like virus (biv) antibodies, had good repeatability. the test was subsequently applied to a bank of serum samples from 928 adult cows from 265 herds in ontario; the number of cows sampled within each herd ranged from 1 to 13. the overall prevalence of anti-biv antibodies among cows was 5.5% with a 95% confidence interval of 4.2% to 7.2%. in contrast, 18.1% of herds had at least one reactor among cows tested ...	1994	8143251
a serological survey of bovine syncytial virus in ontario: associations with bovine leukemia and immunodeficiency-like viruses, production records, and management practices.	of the 920 cows tested, 56.7% showed antiretroviral serological reactivity. prevalence rates (95% confidence interval) of antiretroviral antibodies among individual dairy cows in ontario were: biv 5.5% (4.0-7.0), blv 25.7% (22.9-28.6), and bsv 39.6% (36.4-42.8). the following percentages of cows showed serological reactivity against the specified retroviruses: biv 2.3%, blv 14.0%, bsv 27.5%, biv and bsv 1.3%, biv and blv 0.9%, blv and bsv 9.9%, biv and blv and bsv 0.9%. these rates of sero-posit ...	1995	8548688
associations between farm management practices, productivity, and bovine leukemia virus infection in ontario dairy herds.	the objective of this study was to investigate the associations between herd-level bovine leukemia virus (blv) status and herd-level management and production variables. the study population consisted of 1330 cows sampled from 102 ontario dairy herds. the individual-cow prevalence of blv infection in the population (based on agid testing) was 23%, with 69.6% of herds having one or more positive animals. the herd-level explanatory variables were divided into two datasets containing winter housing ...	1997	9234445
evaluation of a bulk-milk elisa test for the classification of herd-level bovine leukemia virus status.	the results of a commercial bulk-milk enzyme-linked immunosorbent assay (elisa) test for herd-level bovine leukemia virus (blv) status were compared to results obtained from individual agar-gel immunodiffussion (agid) testing on sampled cattle. a positive herd was defined as a herd having one or more agid-positive animals. the estimated true herd status was based on the sensitivity and specificity of the agid test and the number of cattle sampled per herd. ninety-seven herds were used, with a me ...	1997	9234446