Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/4/2002
Publication Date: 4/4/2002
Citation: Interpretive Summary:
Technical Abstract: Frequently, herd expansion results in mixing of cattle from a variety of sources. Unfortunately mixing of cattle populations also means mixing of the diseases they carry. This study involved a herd expansion which combined two existing dairy herds. Cow numbers were inadequate and outside sourcing of animals was necessary. One hundred pregnant heifers were purchased from Canada. Additional cows and heifers were obtained from Minnesota dairies. Isolation, within the limits of practicality, was provided with concurrent vaccination procedures. Label directions were closely followed in vaccination administration and timing. In the fall of 1997, 40 additional late gestation heifers were purchased. These animals were housed at a separate off-site facility to observe a quarantine period and vaccination. The vaccination history of these animals was not available and a blood sample from each animal was taken to evaluate immune status. Titers against BVDV were low (majority of animals < 1:4) in these animals. These animals were not screened for persistent infection. The vaccination program in effect was based on a BVDV1a modified-live vaccine. In the season following the addition of the 40 late-gestation heifers, 48 cows either aborted or experienced early embryonic death. The BVDV isolated from the fetal abortions belonged to the BVDV1b genotype.