Effect of uterine ligation and cervical plugs on retention of frozen-thawed boar sperm.

Two experiments were conducted to determine whether the prevention of retrograde sperm expulsion from the uterus would enhance ovum fertilization by frozen-thawed boar sperm and whether insertion of a cervical plug would reduce the loss of frozen-thawed boar sperm from the uterus. In Exp. 1, 25 gilts were surgically inseminated and one uterine horn was ligated to prevent expulsion of sperm. Nine gilts were killed 4 h after insemination, and the sperm were recovered from the uterine horns and uterotubal sections. Significantly more sperm were recovered from the ligated than from the unligated uterine horns. Fertilized ova were recovered from nine of 16 gilts killed 48 to 90 h after insemination. More ova (P less than .005) were fertilized on the ligated than on the unligated sides of the reproductive tracts (87 vs 64%). In Exp. 2, 24 gilts were artificially inseminated with frozen-thawed boar sperm and then randomly selected to receive the intracervical insertion of a cotton tampon, a plastic plug or no treatment (control). Sperm were recovered from the uterine horns and uterotubal sections 4 h after insemination. The cervical plugs failed to significantly increase the retention of sperm in the uterotubal sections and uterine horns.