title: Pregnancy rates after artificial insemination with cooled stallion spermatozoa either with or without single layer centrifugation.
abstract: A successful outcome after artificial insemination with cooled semen is dependent on many factors, the sperm quality of the ejaculate being one. Previous studies have shown that spermatozoa with good motility, normal morphology, and good chromatin integrity can be selected by means of colloid centrifugation, particularly single layer centrifugation (SLC) using species-specific colloids. The purpose of the present study was to conduct an insemination trial with spermatozoa from "normal" ejaculates, i.e., from stallions with no known fertility problem, to determine whether the improvements in sperm quality seen in SLC-selected sperm samples compared with uncentrifuged controls in laboratory tests are reflected in an increased pregnancy rate after artificial insemination. In a multicentre study, SLC-selected sperm samples and uncentrifuged controls from eight stallions were inseminated into approximately 10 mares per treatment per stallion. Ultrasound examination was carried out approximately 16 days after insemination to detect an embryonic vesicle. The pregnancy rates per cycle were 45% for controls and 69% for SLC-selected sperm samples, which is statistically significant (P < 0.0018). Thus, the improvement in sperm quality reported previously for SLC-selected sperm samples is associated with an increase in pregnancy rate, even for ejaculates from stallions with no known fertility problem.
authors.affiliation: Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden. Electronic address: jane.morrell@slu.se.
authors.forename: J M
authors.initials: JM
authors.lastname: Morrell
authors.affiliation: National Stud Lower Saxony, Celle, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Richter
authors.affiliation: National Stud Lower Saxony, Celle, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Martinsson
authors.affiliation: Flyinge AB, Flyinge Kungsgård, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Stuhtmann
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Hoogewijs
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Roels
authors.affiliation: Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: A-M
authors.initials: AM
authors.lastname: Dalin
mesh_terms: D000818:Animals; D001947:Breeding / Q000379:methods; D002469:Cell Separation; D002498:Centrifugation / Q000379:methods / Q000662:veterinary*; D003080:Cold Temperature; D003102:Colloids; D005260:Female; D005298:Fertility; D006736:Horses / Q000502:physiology*; D007315:Insemination, Artificial / Q000379:methods / Q000706:statistics & numerical data / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*
chemical_list: D003102:Colloids
keywords: Androcoll-E; Cooled stallion semen; Normal ejaculates; Pregnancy