Document Type

Thesis - University Access Only

Award Date

2003

Degree Name

Master of Science (MS)

Department / School

Veterinary and Biomedical Sciences

Abstract

Bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BHV-1) are frequently involved in reproductive failure in dairy cows and in the bovine respiratory complex disease (BRDC) in calves and cows. Both problems impact dairy farm profitability by decreasing pregnancy rates, availability of dairy replacements, and the performance of the heifers affected by those viruses. Twenty Holstein Friesian cows were randomized in two groups. One group of cows was vaccinated with inactivated vaccine (IV) 60 days and 30 days pre-parturn, and the other group of cows was vaccinated with modified live vaccine (ML V) between 15- 30 days post-partum. The titers of each group were monitored beginning at Day 15 after vaccination and every 30 days thereafter for one year. The serology results showed a difference in the humeral response between vaccination programs, where cows vaccinated during the dry period with inactivated vaccine had higher titers. The cellular mediate immune response (CMI) was tested by measuring the amount of interferon gamma (IFN y) in the supernatant of leukocyte culture at 360 days post vaccination and at 15 days after revaccination to evaluate the memory of the immune system. We did not find any difference after one year post vaccination but we found a difference between vaccination programs at 15 days after revaccination in the IFN y production, where cows vaccinated during the dry period with inactivated vaccine had higher IFN y production. To complete the study of the differences between vaccination programs, we analyzed the differences between production and reproductive parameters such as open days, days at first service, service per conception, milk production at 305 days and somatic cell count. In analyzing these parameters we found an increase in somatic cell counts in cows vaccinated with ML V during all the trial In calves born from cows in each vaccination program, we measured then serum neutralizing titers against BHV-1, BVDV types 1 and 2, before colostrum intake, 48 hours afterwards and every 30 days until 90 days of age. We found that calves born from cows vaccinated during the dry period with IV had higher titers for all three viruses. The amount of BVDV specific immunoglobulin (IgG) in the colostrum was measured by blocking ELISA assay. There was no difference in BVDV IgG levels between vaccination programs. This study demonstrated that cows vaccinated during the dry period with IV had higher humeral and cellular response and their calves had higher antibody titer than cows vaccinated with ML V during the postpartum.

Library of Congress Subject Headings

Dairy cattle -- Vaccination -- Evaluation Colostrum

Format

application/pdf

Number of Pages

97

Publisher

South Dakota State University

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