description and first results of a bvdv control scheme in brittany (western france).a collective zoo-sanitary control scheme for bvdv has been implemented in brittany in successive steps since 1998. prior evaluation of prevalence and dynamics of infection through bulk-milk elisa showed that 40% of the dairy herds were likely to be free of bvdv but that, in the long term, no improvement was to be expected without control of new infections. the next step was a test-and-cull programme for pi animals in elisa positive herds. ten percentage of the herds were found to have at least o ...200516242196
large scale assessment of the effect associated with bovine viral diarrhoea virus infection on fertility of dairy cows in 6149 dairy herds in brittany (western france).this study aimed at quantifying on a large scale the risk of both three-week-return-to-service and late-return-to-service for dairy cows according to the bvdv-infection status of the herds. three-week- and late-returns-to-service were defined as a repeat service occurring respectively from 19 to 25 days and after 25 days following a first or a second service. the level of bvdv-specific-antibodies in bulk tank milk were measured four times at four months intervals by a blocking elisa test to defi ...200414643866
assessing the within-herd prevalence of cows antibody-positive to bovine viral diarrhoea virus with a blocking elisa on bulk tank milk.milk samples from 135 herds in brittany were tested by a blocking elisa for antibodies to bovine viral diarrhoea virus (bvdv) and used to assess the relationship between the bulk milk result and the within-herd prevalence of antibody-positive lactating cows. this relationship was first quantified by using a general linear model and controlling for the number of cows contributing milk to the bulk tank, for the percentage of primiparous cows in the herds and for the number of milkings contributing ...200111554568
bulk milk somatic cell counts and bovine viral diarrhoea virus (bvdv) infection in 7252 dairy herds in brittany (western france).variations in test-day bulk milk somatic cell count (bmscc) according to bovine viral diarrhoea virus (bvdv) infection status of the herd were quantified. infection statuses were defined, based on bulk-milk antibodies measured twice 4 months apart. on each test-day, bmscc was calculated as the weighted mean of the individual cow-level somatic cell counts. a total of 97,985 test-days in 7252 herds were considered. the effect of the bvdv-infection on bmscc was assessed using mixed linear models, c ...200516169615
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