Non-surgical Porcine Embryo Transfer by a Balloon Catheter Producing Subsequent High Farrowing Rate

Abstract

The aim of this study was to improve a non-surgical technique for porcine embryo transfer that would be more effective and could be operated as easy as artificial insemination in the pig farm. Embryos were collected surgically from 13 gilts at 5 to 7 days post insemination by flushing uterine horns. A total of 144 embryos were immediately transferred into 11 recipients, 1 sow and 10 gilts, by the transcervical method with 2 types of balloon catheters (FA 361 and FA 1466 catheter, Fujihira Industries, Ltd., Tokyo). The recipient pigs were anesthetized and their heads laid down on the slope fastening their legs securely. After cleaning the external genitalia, the balloon catheter was inserted into the cervix through the vaginal speculum and fixed in the cervical canal by swelling the balloon. The number of embryos ranging from 5 to 26 per pig (Average: 13±6.8), of which developmental stages were morulae to hatched blastocyst, were transferred into the uterine horn through a catheter with a small volume of sterile physiological saline. Nine of 11 recipients (81.8%) got pregnant, while 2 of 9 pregnant pigs had an abortion at early time of gestation. The remaining 7 pigs farrowed a total of 25 live piglets (3.6±1.5). The embryonic survival rate was significantly (P<0.05) higher in the recipients transferred embryos by the catheter FA 1466 than in those by the catheter FA 361, although there was no significant difference in pregnancy rate. Moreover, in the catheter FA 1466-group, the number of young correlated closely with the number of transferred embryos (r=0.99, P<0.01). The results showed that the balloon catheter could be used for non-surgical transfer of porcine embryos, but the embryonic survival rate was affected by the type of catheter.