The role of bovine viral diarrhea in the reproductive tract of boars

The Bovine Viral Diarrhea Virus infection in pigs can result in transient leukopenia, chronic gastroenteritis, septicemia, and hemorrhagic lesions. Both the Classical Swine Fever Virus (CSF) and the Atypical Porcine Pestvirus (APPV) are shedding in semen of infected boars. Because they share conserved regions and present antigenic similarity, they may not be the only species belonging to the genus Pestivirus that can be shed in the semen of infected boars. At first, six trained males were selected for semen collection on a dummy. From those animals were collected blood, semen and preputial swab every four days until the 52nd day after inoculation with BVDV-2. Posteriorly, eight females were acquired and allocated to two groups: the control group (n = 2) and the inseminated group with BVDV-2 contaminated semen (n = 6), aiming to mimic BVDV-2 transmission by artificial insemination. Blood samples from males and females, semen and preputial swab collected, were tested for viral RNA detection by the RT-PCR technique. An aliquot of whole blood from the boars was used to perform hematological analyzes, which showed a significant reduction in monocyte counts and a significant increase in lymphocyte count when comparing periods before and after inoculation with BVDV-2. Neutralizing antibody titers were determined by virus neutralization. None of the animals presented clinical signs and no BVDV-2 shed was observed in the reproductive route nor worsening in the seminal parameters evaluated. Transmission of BVDV-2 via artificial insemination under experimental conditions was not observed. (AU)