title: Effect of cushioned or single layer semen centrifugation before sex sorting on frozen stallion semen quality.
abstract: The aim of this study was to compare the effect of presorting centrifugation (cushioned [CC] or single-layer colloid [SLC]), with simple dilution (SD), on the quality of sex-sorted stallion semen before and after sorting and after freezing and thawing. Four ejaculates from each of two fertile stallions were collected 1 week apart and evaluated for percent total sperm motility (TM), percent viable acrosome-intact sperm (VAI), and DNA quality (percentage of DNA fragmentation index). Freezing caused, independently from CC and SLC treatments, a significant decrease of TM (P < 0.05) and VAI (P < 0.05) in both unsorted and sorted semen. On the other hand, sorting did not impair TM and VAI and, interestingly, improved DNA quality in all treatments only before freezing (28 vs 13, 28 vs 10, 22 vs 7 in SD, CC, and SLC for unsorted vs sorted groups, respectively; P < 0.05); this positive effect was lost in the same samples after freezing and thawing, suggesting that the freezing process reduces the DNA quality of sex-sorted sperm. Our results suggest that CC and SLC are not able to select those spermatozoa that possess a better ability to withstand sperm processing associated with sperm sorting and freezing.
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy; Artificial Insemination Center (AUB-INFA), University of Bologna, Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Mari
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy. Electronic address: diego.bucci3@unibo.it.
authors.forename: D
authors.initials: D
authors.lastname: Bucci
authors.affiliation: Department of Large Animal Clinical Sciences, Texas A&M University College of Veterinary Medicine, College Station, Texas, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Love
authors.affiliation: Artificial Insemination Center (AUB-INFA), University of Bologna, Bologna, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Mislei
authors.affiliation: Artificial Insemination Center (AUB-INFA), University of Bologna, Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Rizzato
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Giaretta
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Merlo
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Spinaci
mesh_terms: D000818:Animals; D002498:Centrifugation / Q000379:methods / Q000662:veterinary*; D003102:Colloids; D006736:Horses / Q000502:physiology*; D008297:Male; D012662:Semen Preservation / Q000662:veterinary*; D012743:Sex Preselection / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D003102:Colloids
keywords: Cushioned centrifugation; Horse; Sexed semen; Single-layer colloid; centrifugation