Estimated BVDV-prevalence, -contact and -vaccine use in dairy herds in Northern Portugal.
A study to evaluate BVDV-prevalence, recent -contact and -vaccine use in dairy herds in the "Entre Douro e Minho" (EDM) region in North Portugal was carried out in 124 dairy herds in 2003. Herds were visited to ascertain BVDV-vaccine use and to collect a bulk tank milk (BTM) sample and serum from 1268 cattle to analyse BVDV-antibodies using an NS2-3 ELISA. Fifty-three percent of farmers used inactivated BVDV-vaccines whilst the remaining farmers were not presently using BVDV-vaccines. BMT-antibody results included 35% positives, 25% negative and 39% inconclusive, and were similar in vaccinated and non-vaccinated herds (p>0.05) and allowed estimating a 10% BVDV herd-prevalence from prior knowledge of the relationship between BMT-antibody results and probability of PI cattle in the herd. Overall individual seroprevalence was 27% and was 23% in non-vaccinated and 36% in vaccinated cattle (p<0.05). Contact of the herd with BVDV was assessed according to seroprevalence in young and adult cattle in the herd and it was estimated that 35% of herds were infected or had recent contact with BVDV, 40% were not infected and did not have recent contact with BVDV and the BVDV-infection and -contact status of remaining herds was undetermined. The results from this study indicate BVDV is endemic and BVDV-vaccines are widespread in the dairy-cattle population in EDM region in Portugal.
Niza-Ribeiro
J
J
Segalab S.A., Rua de Recarei, Leça do Balio, 44566-734 Leça do Balio, Portugal. niza.ribeiro@agros.pt
Pereira
Adelaide
A
Souza
João
J
Madeira
Helena
H
Barbosa
Abigaíl
A
Afonso
Carla
C
D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D002353:Carrier State / Q000662:veterinary; D002417:Cattle; D003612:Dairying; D011174:Portugal / Q000453:epidemiology; D015995:Prevalence; D016036:Seroepidemiologic Studies; D014765:Viral Vaccines / Q000008:administration & dosage*
D014765:Viral Vaccines