A PROTOCOL FOR IN-VITRO MATURATION AND FERTILIZATION OF SHEEP OOCYTES

Two in vitro maturation (IVM) and fertilization (NF) protocols were ev aluated with the objective of improving upon a protocol that will opti mize NF-assisted reproduction in sheep. There was no attempt to compar e possible confounding effects within protocol. The addition of follic le-stimulating hormone (FSH) and luteinizing hormone (LH) to the matur ation (IVM) medium significantly enhanced ovine oocyte maturation as c ompared to human chorionic gonadotropin (hCG) alone. Oocytes fertilize d in vitro with spermatozoa treated with calcium ionophore A23187 and caffeine in Brackett and Oliphant medium (Protocol 1) significantly im proved oocyte fertilization and embryo development in vitro than with spermatozoa separated by swim-up in synthetic oviduct fluid containing estrus ewe serum (Protocol 2). Embryos derived from oocytes matured i n medium containing FSH and LH and fertilized with Protocol 1 were tra nsferred to synchronized recipients and resulted in the birth of lambs . This protocol may be useful for assisted reproduction in sheep. (C) 1998 Elsevier Science B.V. All rights reserved.