title: Effect of bovine viral diarrhea virus infection on fertility of dairy heifers.
abstract: A prospective field study in heifers from birth to first breeding was undertaken on two commercial dairies to assess the effect of bovine viral diarrhea virus (BVDV) congenital and post-natal infection (PNI) on fertility. A high BVDV Type 2 antibody titer (1:4096) at 10 months of age was associated with 32 more days to conceive, compared with a low titer (1:128). Conversely, infection with BVDV by 5-6 months of age and high BVDV Type 2 titers 1 month before conception or breeding was associated with improved fertility. Heifers with evidence of congenital BVDV infection had lower fertility than non-infected heifers (15-42 days longer time-to-first AI), which depended on BVDV Type 2 titers at 10 months of age. Neospora caninum infection was associated with additional services per conception (SPC) and Leptospira interrogans infection was associated with a delay in the time-to-first breeding. It appears that under field conditions, the effect of subclinical BVDV infection on subsequent heifer fertility may be due to a complex of interrelationships among multiple BVDV infections that depend on the type and timing of infection relative to reproductive development and events.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. munozzan@umn.edu
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Muñoz-Zanzi
authors.forename: Mark C
authors.initials: MC
authors.lastname: Thurmond
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Hietala
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D030242:Diarrhea Virus 2, Bovine Viral / Q000276:immunology; D005260:Female; D005306:Fertilization; D030243:Hemorrhagic Syndrome, Bovine / Q000150:complications*; D007247:Infertility, Female / Q000662:veterinary* / Q000821:virology; D007315:Insemination, Artificial / Q000662:veterinary; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral