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Detection of bovine viral diarrhea virus in semen obtained after inoculation of seronegative postpubertal bulls

M. Daniel Givens DVM, PhD1, Allen M. Heath DVM, MS2, Kenny V. Brock DVM, PhD3, Bruce W. Brodersen DVM, PhD4, Robert L. Carson DVM, MS5, and David A. Stringfellow DVM, MS6
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  • 1 Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn University, AL 36849.
  • | 2 Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn University, AL 36849.
  • | 3 Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn University, AL 36849.
  • | 4 University of Nebraska Veterinary Diagnostic Center, 207 Ag Hall, Lincoln, NE 68583.
  • | 5 Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn University, AL 36849.
  • | 6 Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn University, AL 36849.

Abstract

Objective—To evaluate persistence of bovine viral diarrhea virus (BVDV) in semen after inoculation of postpubertal bulls.

Animals—Three 2-year-old bulls and five 6-month-old calves.

Procedure—3 seronegative 2-year-old bulls were inoculated intranasally with BVDV. Serum and semen samples were obtained at regular intervals until 7 months after inoculation. Serum samples were tested for BVDV by use of virus isolation (VI) and reverse transcription-nested polymerase chain reaction (RTnPCR) tests. Semen samples were tested for virus by use of VI and RT-nPCR tests. Testicular biopsy specimens were obtained 7 months after inoculation and tested for BVDV by use of immunohistochemical analysis and VI and RT-nPCR tests. Semen samples collected from 1 bull immediately before and 5 and 7 months after inoculation were administered IV to seronegative calves, which were monitored for subsequent viremia and seroconversion.

Results—Use of VI and RT-nPCR tests detected transient virus in serum of all bulls. The VI test detected BVDV in semen of 2 bulls for < 21 days after inoculation, whereas RT-nPCR assay detected BVDV until 7 months after inoculation. Virus was detected in testicular biopsy specimens of these 2 bulls by use of immunohistochemical analysis and RT-nPCR assay but could only be isolated from the biopsy specimen of 1 bull. Of the calves administered semen IV to detect infectious virus, only the recipient of semen collected 5 months after inoculation of the adult bull was viremic and seroconverted.

Conclusions and Clinical Relevance—Bovine viral diarrhea virus can persist in semen of acutely infected bulls for several months after exposure. (Am J Vet Res 2003;64:428–434)

Abstract

Objective—To evaluate persistence of bovine viral diarrhea virus (BVDV) in semen after inoculation of postpubertal bulls.

Animals—Three 2-year-old bulls and five 6-month-old calves.

Procedure—3 seronegative 2-year-old bulls were inoculated intranasally with BVDV. Serum and semen samples were obtained at regular intervals until 7 months after inoculation. Serum samples were tested for BVDV by use of virus isolation (VI) and reverse transcription-nested polymerase chain reaction (RTnPCR) tests. Semen samples were tested for virus by use of VI and RT-nPCR tests. Testicular biopsy specimens were obtained 7 months after inoculation and tested for BVDV by use of immunohistochemical analysis and VI and RT-nPCR tests. Semen samples collected from 1 bull immediately before and 5 and 7 months after inoculation were administered IV to seronegative calves, which were monitored for subsequent viremia and seroconversion.

Results—Use of VI and RT-nPCR tests detected transient virus in serum of all bulls. The VI test detected BVDV in semen of 2 bulls for < 21 days after inoculation, whereas RT-nPCR assay detected BVDV until 7 months after inoculation. Virus was detected in testicular biopsy specimens of these 2 bulls by use of immunohistochemical analysis and RT-nPCR assay but could only be isolated from the biopsy specimen of 1 bull. Of the calves administered semen IV to detect infectious virus, only the recipient of semen collected 5 months after inoculation of the adult bull was viremic and seroconverted.

Conclusions and Clinical Relevance—Bovine viral diarrhea virus can persist in semen of acutely infected bulls for several months after exposure. (Am J Vet Res 2003;64:428–434)