نتایج جستجو برای: in 472 herds
تعداد نتایج: 16977100 فیلتر نتایج به سال:
OBJECTIVE To evaluate sensitivities at the herd level of test strategies used in the Voluntary Johne's Disease Herd Status Program (VJDHSP) and alternative test strategies for detecting dairy cattle herds infected with Mycobacterium paratuberculosis. DESIGN Nonrandom cross-sectional study. SAMPLE POPULATION 64 dairy herds from Pennsylvania, Minnesota, Colorado, Ohio, and Wisconsin. Fifty-si...
A bulk milk quality assurance programme for Mycobacterium avium subsp. paratuberculosis (Map) in dairy herds was simulated with a stochastic simulation model (JohneSSim). The aim of this study was to evaluate the epidemiological and economic effects of preventive management measures and various test schemes in a simulated population of closed Dutch dairy herds over a 20-year period. Herds were ...
Bovine rotaviruses isolated from beef and dairy herds in Argentina were serotyped by the immunoperoxidase focus reduction assay as previously described (G. Gerna, M. Battaglia, G. Milenesi, N. Passarani, E. Percivalle, and E. Cattaneo, Infect. Immun. 43:722-729, 1984). Three strains from beef herds were related to the UK and NCDV bovine rotavirus strains defined as serotype 6 (Y. Hoshino, R. G....
OBJECTIVE To estimate seroprevalence of Mycobacterium avium subsp paratuberculosis (MAP) infection among adult dairy cows in Colorado and determine herd-level factors associated with the risk that individual cows would be seropositive. DESIGN Cross-sectional observational study. ANIMALS 10,280 adult (> or = 2 years old) dairy cows in 15 herds in Colorado. PROCEDURE Serum samples were test...
The objectives of this study were to determine by-parity nonproductive female days (NPD or NPDs) and mating and culling measurements, to determine correlations between by-parity NPDs, mating and culling measurements and herd productivity measurements, and to compare by-parity NPDs between three herd groups (105 herds) with differing reproductive productivities. NPD was defined as the number of ...
Effectiveness of long-term anti-BVDV vaccination program in reducing prevalence of persistent BVDV infection in cattle herds was evaluated in seven years observational study (2005-2011). Among three seropositive dairy cattle herds (within herd seroprevalence 100%, confirmed by ELISA Herd Check BVDV Ab, IDEXX, Sweden) vaccination program based on inactivated vaccine (cytopathic strain 5960) was ...
Epidemiological data describing bovine herpesvirus 1 (BoHV-1) infection in Brazilian cattle herds are scarce. A cross-sectional study was conducted in the state of Paraná between December 2001 and July 2002 with the objective of estimating the apparent prevalence of BoHV-1-seropositive herds and animals and identifying the potential risk factors for infection in farms with breeding animals in t...
Background: Fasciola hepatica is a helminth parasite of global importance in livestock, with major economic impact. However information on F. hepatica infections in Irish pasture-based dairy herds is limited. Therefore this study was conducted in order to determine the prevalence, seasonality and management factors associated with F. hepatica. A total of 319 Irish dairy herds were selected for ...
Porcine proliferative enteropathy (PPE) caused by Lawsonia intracellularis (LI) is one of the most important enteric diseases in growing swine. The acute form of this disease, proliferative hemorrhagic enteropathy (PHE), has become a common problem when replacement breeding stock are introduced into a herd. In the cases described, animals of different immune status were moved between supply and...
Feeding practices, ration composition, and body condition scores (BCS) were assessed in an observational case-contrast study of Norwegian dairy herds with low (n = 98) and high (n = 94) mastitis infection rates. Differences between the 2 groups of herds were associated with feeding practices and amount of roughage. More herds in the low-infection group were fed a reduced amount of roughage at d...
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