IN-VITRO FERTILIZATION OF BOVINE OOCYTES WITH SEMEN FROM BULLS PERSISTENTLY INFECTED WITH BOVINE VIRAL DIARRHEA VIRUS

Semen from three bulls persistently infected with bovine viral diarrhea virus (BVDV) was used for production of embryos by in vitro fertilization (IVF). The percentages of oocytes which cleaved and the percentages of embryos which developed to blastocysts were 47%, 51%, 20% and 17%, 20%, 13% using semen from the BVDV infected bulls, and 53% and 22% using pooled semen from three uninfected bulls. The fertilization rates for semen of infected bulls were 68%, 70%, 55% and 75% for control non-infected semen (P> 0.05). No infectious virus was isolated from samples of follicular fluid, oocytes and oviductal cells used for IVF or from any of the embryos produced by IVF. Sperm samples ('swim up') from infected bulls used for insemination and media used to wash inseminated oocytes tested positive. When BVDV non-cytopathic strain (10(5) TCID50 ml-1) was added to sperm from uninfected bulls prior to IVF, 49% of ova cleaved and 22% developed to the blastocyst stage compared with 5 3% ova cleaved and 35% blastocyst for control uninfected semen (P> 0.05). All the embryos tested negative for the presence of BVDV.