Laparoscopic oviductal transfer of in vitro matured and in vitro fertilized bovine oocytes

The objective of this study was to obtain normal pregnancy following laparoscopic oviductal transfer of in vitro matured and fertilized bovine oocytes. Methods for in vitro maturation and in vitro fertilization were similar to those previously reported (1). Primary oocytes judged to be potentially viable were cultured for 26 h in modified TCM 199 supplemented with heat-treated fetal calf serum (20% v/v), 5mug/ml FSH (USDA-bFSH-B-1), and 1mug/ml estradiol 17-beta. Oocyte cumulus complexes were microscopically evaluated for maturation (first polar body formation) following a brief treatment with hyaluronidase. Mature oocytes were inseminated with heparin-treated spermatozoa and incubated at 39 degrees C under paraffin oil and moist 5% CO(2), 5% O(2), 90% N(2). In this work, 450 oocytes were recovered at slaughter from ovaries of 42 random cows of unknown reproductive status and 336 oocytes (74.7%) with compact cumulus were selected for culture. Of these, 322 (95.4%) matured in vitro. Of 218 inseminated oocytes, 198 (90.8%) were penetrated by sperm and 83 (38.1%) cleaved, with 102 (46.6%) of the embryos reaching four- to eight-cell stages. None of 40 oocytes not exposed to sperm and none of 30 oocytes inseminated with untreated sperm showed signs of activation. In a control experiment with hormones added, 105 of 115 (91.3%) oocytes matured in vitro and 20 of 105 (19.5%) cleaved following in vitro insemination. Laparoscopy was performed on four synchronized recipients under local anesthesia. A catheter containing three embryos in the two to four cell stages was passed through the operating channel of a direct viewing bronchoscope for deposition in the oviduct ipsilateral to the recipients developing corpus luteum while the fimbria and the mesovarium were manipulated with Semm's forceps. A normal term pregnancy confirmed in vitro fertilization and provides feasibility data for use of laparoscopic methodology developed in this work for testing viability of bovine oocytes and embryos. These results are encouraging for the application of in vitro maturation and in vitro fertilization for overcoming infertility in domestic and endangered species.