title: 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).
abstract: 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 define five BVDV-infection-herd-statuses: (i) presumed non-infected herds for a long time, (ii) presumed not-recently-infected herds, (iii) presumed past-infected-recently-recovered herds, (iv) presumed past-steadily-infected herds, (v) presumed recently-infected herds. A total of 150,854 AIs from 122,697 cows in 6149 herds was included in the analysis. The risk of return-to-service was assessed using logistic regression and survival analysis models. The BVDV-infection-herd-status was not significantly associated with the risk of 3-week-return-to-service, but significantly with that of late-return-to-service. Cows in herds presumed past-infected-recently-recovered, past-steadily-infected, or recently-infected had a significantly higher risk of late-return-to-service (relative risk of 1.03, 1.11, 1.12, respectively) compared with cows in herds presumed not-recently-infected. Risk of late-return-to-service was not significantly different in cows from herds presumed non-infected for a long time or not-recently-infected. In conclusion, BVDV-infection was found to mainly increase the risk of embryonic and foetal death.
authors.affiliation: Unit of Animal Health Management, Veterinary School INRA, BP 40706, 44307 Nantes 03, France. arobert@vet-nantes.fr
authors.forename: A
authors.initials: A
authors.lastname: Robert
authors.forename: F
authors.initials: F
authors.lastname: Beaudeau
authors.forename: H
authors.initials: H
authors.lastname: Seegers
authors.forename: A
authors.initials: A
authors.lastname: Joly
authors.forename: J M
authors.initials: JM
authors.lastname: Philipot
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000150:complications* / Q000821:virology; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology; D005260:Female; D005313:Fetal Death / Q000662:veterinary / Q000821:virology; D005602:France; D007247:Infertility, Female / Q000662:veterinary* / Q000821:virology; D007315:Insemination, Artificial / Q000662:veterinary; D016015:Logistic Models; D008892:Milk / Q000821:virology; D011247:Pregnancy; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral