| Abstract: | An opportunity for study of the potential role of semen in the transmission of bovine leukosis virus (BLV) was provided when a Jersey herd was found to be BLV-seronegative. This was a closed herd; new genetic material had been introduced by artificial insemination (AI), using semen collected and processed at 7 AI centers in the United States. Of 66 donor bulls from which semen had been collected for AI use in the herd during the 5 years the herd remained seronegative, 24 were consistently BLV-seropositive and 2 became seropositive for BLV during the study. Semen collected from the BLV-seropositive bulls accounted for 1,019 semen units, representing 48.3% of the semen purchased. The maintenance of BLV seronegativity in this herd for 5 years, when semen from BLV-seropositive bulls was used for AI, provided evidence for the lack of infectivity of BLV in bovine semen. |
