title: Effect of dialysis or centrifugation on post-thaw motility and fertility of Santa Gertrudis bull semen collected by electroejaculation.
abstract: Electroejaculated semen from Santa Gertrudis bulls was used to study the effect of centrifugation (600 x g for 5 min) or dialysis [molecular weight cutoff <14,000 Daltons (Da)] on post-thaw motility and on fertility in beef cattle. Analysis of post-thaw motility showed that the main effects (bulls and semen treatment) were significant (P<0.05). Dialysis significantly improved post-thaw motility in four of seven bulls. Initial volume of seminal plasma in the ejaculate was negatively correlated to post-thaw motility (r = -0.73). No significant improvement in post-thaw motility was observed for bulls with high volumes of ejaculate. In a fertility trial, calving rates of heifers synchronized with PGF(2)alpha and inseminated at 72 and 96 h after the second PGF(2)alpha injection with dialyzed or commercial semen were not statistically different (P>0.05; 54.4% vs 55.4%). These results show that dialysis could be used to improve post-thaw motility of electroejaculated bull semen without altering its fertilizing capacity. However, a high initial volume of seminal plasma seems to have a deleterious effect on sperm freezability that cannot be reversed by dialysis.
authors.affiliation: Department of Reproduction, Institute of Agronomy and Veterinary Medicine, Hassan II, Rabat-Instituts BP 6202, Morocco.
authors.forename: A
authors.initials: A
authors.lastname: Tibary
authors.forename: E F
authors.initials: EF
authors.lastname: Graham
authors.forename: A
authors.initials: A
authors.lastname: Asri
authors.forename: R
authors.initials: R
authors.lastname: Boukhliq
authors.forename: R
authors.initials: R
authors.lastname: Deyo