ENDOSCOPIC EMBRYO COLLECTION AND EMBRYO-TRANSFER INTO THE OVIDUCT ANDTHE UTERUS OF PIGS

We describe the first complete embryo transfer program, including flus hing of embryos from the oviducts via the uterine hems, transfer of em bryos into the Fallopian tubes or the uterine horns and recording of t he number of piglets born live. The described procedure is minimally i nvasive and allows the use of pigs simultaneously for embryo collectio n and production of normal pregnancies. A 30 degrees forward oblique e ndoscope provided optimal visualization of the reproductive organs and free access to the organs for embryo flushing and transfer. In contra st to surgical and nonsurgical methods, endoscopy allows to pre-examin e the genital tract for reproductive abnormalities and successful ovul ation. A total of 95 prepuberal gilts or cyclic sows were used in this trial. Embryos or oocytes were collected from hormonally treated pigs via endoscopy (n = 17) on Day 3 and via laparotomy or post mortem aft er slaughter (control group, n = 38) on Day 3 and 6 after insemination . One (unilateral collection, n = 7) or both oviducts (bilateral colle ction, n = 10) were flushed endoscopically. We recovered 114 (average 16/pig) and 279 (average 28/pig) oocytes or embryos with fertilization rates of 89% and 72%, respectively. In the control group 834 oocytes or embryos were collected at Day 3 and 6 after insemination (fertiliza tion rate 64%, total 534 embryos, 33 at 2-, 367 at 4-, 2 at 8-cell sta ge, 24 morulae and 108 blastocysts). Of 836 embryos recovered by endos copy, surgery or slaughter 528 Day 3 embryos at 2- to 4-cell stage wer e transferred into (one) oviducts (n = 27 pigs, about 20/pig) resultin g in 9 pregnant pigs diagnosed at Day 28 by sonography. Of the 9, 8 ca rried a total of 49 piglets to term. A total of 195 Day 6 embryos were transferred into uterine hems (n = 12 pigs, about 16/pig), resulting in 5 pregnant pigs carrying a total of 38 offspring to term. The use o f endoscopy in assisted reproduction of pigs has the advantages of all owing easy access to the ovary, oviduct and uterus, clear view of the organ manipulation without exposure and exteriorization of viscera dur ing surgery. (C) 1997 by Elsevier Science Inc.