title: Comparison of culture and insemination techniques for equine oocyte transfer.
abstract: This study was designed to test 3 approaches for insemination and transfer of oocytes to recipient mares. Oocytes were recovered transvaginally from naturally cycling donor mares 24 to 26 h after an intravenous injection of 2500 IU of hCG when follicles reached 35 mm in diameter. Multiple oocytes (1 to 4) were transferred surgically into the oviducts of 4 or 5 recipient mares per group. Three groups of transfers were compared: 1) transfer of oocytes cultured in vitro for 12 to 14 h postcollection with insemination of the recipient 2 h postsurgery; 2) transfer of oocytes into the oviduct within 1 h of collection, with completion of oocyte maturation occurring within the oviduct, and insemination of the recipient 14 to 16 h postsurgery; and 3) transfer of spermatozoa and oocytes (cultured 12 to 14 h in vitro) into the oviduct. Numbers of embryos detected by Day 16 of gestation were not different (P>0. 1) for groups 1, 2, and 3 (57%, 43% and 27%). Therefore, equine oocytes successfully completed the final stages of maturation within the oviduct, and sperm deposited within the oviduct were capable of fertilizing oocytes.
authors.affiliation: Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins 80523, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Carnevale
authors.forename: L J
authors.initials: LJ
authors.lastname: Maclellan
authors.forename: M A
authors.initials: MA
authors.lastname: Coutinho da Silva
authors.forename: T J
authors.initials: TJ
authors.lastname: Scott
authors.forename: E L
authors.initials: EL
authors.lastname: Squires
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D015181:Gamete Intrafallopian Transfer / Q000379:methods / Q000662:veterinary*; D006736:Horses / Q000502:physiology*; D001239:Inhalation; D007315:Insemination, Artificial / Q000662:veterinary; D007813:Laparotomy / Q000662:veterinary; D008297:Male; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000502:physiology; D011247:Pregnancy
chemical_list: D006063:Chorionic Gonadotropin