Artificial insemination of gilts with porcine reproductive and respiratory syndrome (PRRS) virus-contaminated semen

Six gilts were artificially inseminated (AI) with extended semen from a boar free of porcine reproductive and respiratory syndrome (PRRS)virus infection. One week later, the same boar was inoculated intranasally with PRRSvirus. Seven days after inoculation,the boar was used to AI an additional five gilts. All II gilts were bred 3 days in a row using freshly collected and extended semen on each of the 3 days.Gilts were bled on a weekly basis until they were euthanized. Serum samples were tested for the presence of PRRSvirus antibodies by the indirectfluorescent antibody (IFA) test and for the presence of PRRS virus using virus isolation on porcine alveolar macrophages.Due to the cytotoxic nature of semen for continuous cell lines, a swine bioassaywas used to confirm the presence of PRRSvirus in the semen. The boar was euthanized on day 2 I postchallenge.The control gilts were euthanized on day 40 and the gilts exposed to PRRSvirus-contaminated semen were euthanized on day 34 following the first insemination. Reproductive tract tissueswere collected for virus isolation and histopathologic examination.