title: Comparison of pregnancy rates achieved with frozen semen using two packaging methods.
abstract: The pregnancy rate achieved with frozen semen using two packaging methods was compared in two separate experiments. The sperm-rich fraction of the semen was collected and immediately extended in an egg-yolk based extender to a final concentration of 100 x 10(6) sperm/ml. Half of each ejaculate was packaged in 4.0-ml plastic straws and the other half in 10-to 12-ml flattened aluminum tubes. After detection of a 35-mm follicle, mares were inseminated daily until ovulation. Pregnancy was detected, and embryonic vesicle size was measured by ultrasonic echography Days 14 to 26 after ovulation. The one-cycle pregnancy rate achieved using both packaging methods was 50% overall (23 46 ), with 46% (12 26 ) and 55% (11 20 ) rates achieved, respectively, using straws and aluminum tubes. These rates were not significantly different.
authors.affiliation: Hofmann Center for Reproductive Studies New Bolton Center-University of Pennsylvania School of Veterinary Medicine Kennett Square, PA 19348 USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Love
authors.forename: W L
authors.initials: WL
authors.lastname: Loch
authors.forename: F
authors.initials: F
authors.lastname: Bristol
authors.forename: M C
authors.initials: MC
authors.lastname: Garcia
authors.forename: R M
authors.initials: RM
authors.lastname: Kenney