COLLECTION AND TRANSFER OF MICROINJECTABLE EMBRYOS FROM DAIRY GOATS

This pilot project was designed to optimize the collection and transfer of microinjectable embryos. Does were synchronized with norgestomet (6 mg) ear implants between December 1987 and April 1988. Implants remained for at least 14 d, and does were superovulated with one of the following: Treatment 1, PMSG (1000 IU) 24 h prior to implant removal; Treatment 2, FSH-P (20 mg) over 4 d, beginning 48 h prior to implant removal; or Treatment 3, FSH-P (24 mg) over 3 d, beginning 24 h prior to implant removal. Animals in Treatment 2 were in estrus by 24 h, in Treatment 3 within 36 h, and in Treatment 1 between 24 and 48 h post implant removal. Treatment 2 had the largest number of ovulations (-x=19.8) and the largest collection of both embryos and unfertilized oocytes (-x=13.6). The collection of fertilized embryos was higher in Treatment 3 (-x=5.0) than in Treatment 2 (-x=2.6) or Treatment 1 (-x=2.7). One-cell embryo collection was optimized by collecting 72 to 79 h following implant removal. All embryos were microinjected with 2 to 3 picol of tris-EDTA buffer into the male pronucleus. Of seven recipient does receiving a total of 34 injected embryos, three (43%) maintained pregnancy and six kids were born. These data establish regimens for superovulation/ synchronization and timing of pronuclear embryo collection for dairy goats for the purpose of microinjection. © 1990.