Experimental collection and transfer of embryos from bovine immunodeficiency virus (BIV) infected cattle

Three experiments were conducted to determine whether the lentivirus, bovine immunodeficiency virus (BIV) is likely to be transmitted via embryo transfer. In the first experiment, embryos collected from BIV-negative heifers were exposed in vitro to BIV for 24 h, washed and then tested for the presence of the provirus. In the second experiment, embryos obtained from BIV-negative heifers were transferred to the uterine horns of BIV-infected heifers; 24 h later these embryos were recovered and tested for the presence of BIV. In the third experiment, embryos were collected from heifers experimentally infected with BIV and then transferred to BIV-negative recipients. In all three experiments, (BIV) proviral DNA was not detected by PCR in association with any oocytes, embryos, follicular fluid, oviductal or uterine washes. Twelve single embryos collected from BIV experimentally infected donors were transferred to BIV-negative recipients resulting in the birth of 7 calves all of which were also negative for BIV; the recipients remained BIV-negative throughout the experiment. In conclusion, this study demonstrates that it is possible to produce transferrable stage embryos from donors infected with BIV and that such embryos are unlikely to transmit this agent either to the recipients or the resulting offspring.