title: Duration of thawing on post thaw acrosome morphology and motility of boar spermatozoa frozen in 5-ml maxi-straws.
abstract: Ejaculates from six boars were frozen in 5-ml maxi-straws and stored in liquid nitrogen. Maxi-straws were thawed by submersion in a 52 degrees C circulating waterbath for 28, 34, 40, 46, 52, or 58 sec. The post thaw percentages of motile sperm and acrosomes with a normal apical ridge (NAR) at the initial microscopic examination were significantly higher (P < 0.05) for maxi-straws submerged for 40 sec than for any other duration of submersion. The mean core temperature of maxi-straws after 40 sec of submersion was 4.8 degrees C. Based on regression equations for post thaw motility and NAR acrosomes, a 37 sec thawing time would be expected to provide the maximal post thaw survival for boar sperm frozen in maxi-straws.
authors.affiliation: Reproduction Laboratory, Animal Science Institute, Beltsville Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705 USA.
authors.forename: V G
authors.initials: VG
authors.lastname: Pursel
authors.forename: C S
authors.initials: CS
authors.lastname: Park