A province-wide, cross-sectional seroprevalence and agroecological risk factor study of Mycobacterium avium subspecies paratuberculosis (MAP), Neospora caninum (NC), Bovine leukemia virus (BLV), and Bovine viral diarrhea virus (BVDv) genotypes 1 and 2 (BVDv1 and BVDv2) infection in dairy cattle herd...

Of 1204 dairy cows and 1425 beef cows sampled, 60.8% and 10.3% were seropositive for Bovine leukemia virus, 4.5% and 1.7% were seropositive for Mycobacterium avium subspecies paratuberculosis, and 8.3% and 9.1% were seropositive for Neospora caninum, respectively, while 28.1% of dairy herds had unva...

An investigation into bacterial water quality problems was conducted on an interconnected stream and irrigation system within the Oldman River Basin of southern Alberta, Canada. Levels of indicator bacteria, including fecal coliforms, generic Escherichia coli and fecal streptococci, were repeatedly ...

Current models or frameworks used to represent and/or conduct research on determinants of human health have lagged behind in adopting emerging concepts of ecosystems: multiple spatial and temporal scales; nested hierarchies of socioeconomic and biophysical environments; inherent complexity of interr...

Rev. of Principles and exposure measurement in epidemiology, by B. Armstrong, E. White, and R. Saracci

Twenty-two Costa Rican dairy herds were actively monitored for vesicular diseases between November 1991 and March 1992, in anticipation of the annual dry season occurrence of vesicular stomatitis (VS). Thirty-nine confirmed cases of VS were concentrated on nine farms, resulting in an average herd in...

With increasing levels of anthelmintic resistance worldwide and a growing demand to produce more organic products, utilisation of control strategies for gastrointestinal nematodes (GIN) that minimize the use of anthelmintics becomes even more important. This study evaluated the farm-level performanc...

Blood was drawn from 1530 dairy cows in 51 herds. For antibodies against bovine leukemia virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum, 37.4%, 2.7%, and 5.6% of cows were test positive, respectively, while 29.2% of herds had unvaccinated animals with > or = 1:64 for...

Rev. of Bovine viral diarrhea virus: diagnosis, management and control, by S.M. Goyal and J.F. Ridpath

BACKGROUND: Nitrate and atrazine are two chemicals that are heavily used in certain sectors of agriculture. They are suspected to be associated with the development of certain types of tumours. METHODS: Existing data were obtained on the incidence of specific types of cancers, contamination of drink...

Scientific certainty regarding environmental toxin-related etiologies of breast cancer, particularly among women with genetic polymorphisms in estrogen metabolizing enzymes, is lacking. Fungicides have been recognized for their carcinogenic potential, yet there is a paucity of epidemiological studie...

The ELISA tests that are available to detect an infection with Mycobacterium avium subsp. paratuberculosis (MAP) have a limited validity expressed as the sensitivity (Se) and specificity (Sp). In many studies, the Se and Sp of the tests are treated as constants and this will result in an underestima...

OBJECTIVE: To determine the value of a commercially available test for measurement of luteinizing hormone (LH) concentrations for its use in distinguishing between ovariectomized and sexually intact bitches. DESIGN: Prospective longitudinal cohort study. ANIMALS: 101 sexually intact bitches and 199 ...

The objectives of this study were: 1) to determine if bulk tank milk urea nitrogen (BTMUN) and whole herd weighted average of the individual cow MUN levels (WHMUN) were equivalent measurements of herd MUN status; and 2) to determine the seasonal variation in BTMUN concentrations in Prince Edward Isl...

The purpose of this study was to survey the seroprevalence of infection with the agents of production-limiting diseases in dairy cattle in New Brunswick, Nova Scotia, and Prince Edward Island. In 30 randomly selected herds per province, 30 cattle per herd were randomly selected and tested for antibo...

Survey responses from 75 randomly selected dairy producers on Prince Edward Island were summarized to obtain a demographic picture of the dairy industry in this province and to determine information management practices and demands for the future. The results indicate a preparedness for dairy produc...

The primary purpose of this research was to determine associations among seropositivity for bovine leukemia virus (BLV), bovine viral diarrhea virus (BVDV), Mycobacterium avium ssp. paratuberculosis (MAP), and Neospora caninum (NC) and each of 3 outcome variables (305-d milk, fat, and protein produc...

The purpose of this study was to evaluate the reliability (precision and accuracy), and repeatability of an infrared method of determining milk urea nitrogen. The reference method used for the reliability assessment was a wet-chemistry, enzymatic determination of milk urea nitrogen. Reliability and ...