Effect of bovine viral diarrhea virus infection on fertility of dairy heifers |
| |
Authors: | Muñoz-Zanzi Claudia A Thurmond Mark C Hietala Sharon K |
| |
Institution: | Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. munozzan@umn.edu |
| |
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. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|