title: [The influence of centrifugation on quality and freezability of stallion semen].
abstract: The aim of the present study was to investigate the influence of various centrifugation methods on sperm loss and quality of frozen-thawed semen. From at a total of 8 Warmblood stallions of the National Stud Farm in Avenches, 3 ejaculates each were collected and seminal plasma was removed using 3 different centrifugation regimes. In method I (reference method) centrifugation occurred by a speed of 600 x g during 10 minutes. In method II 1000 x g was used during 2 minutes while in method III centrifugation was performed by 2000 x g during 2 minutes. After centrifugation 90%, of the supernatant was removed and sperm loss calculated. After resuspension of the pellet with freezing medium, functional membrane integrity was evaluated by HOS-test and motility determined. In frozen-thawed semen motility, viability as well as functional membrane integrity (HOS-test) and acrosome status using chlortetracyclinassay (CTA) were assessed. Our results demonstrate that mean sperm loss (I, 1.9%; II, 8.7%; III, 3.7%) was significantly (P < 0.05) different between the three centrifugation regimes. Regarding semen quality of frozen-thawed semen, HOS in method III (52.1%) was significantly lower than in methods I (55.5%) and II (55.3%). Evaluation of the acrosome status by CTA showed that more than 70% of sperm cells were capacitated and 25% capacitated and acrosome reacted. From our results we conclude that sperm loss and functional membrane integrity (HOS-test) in frozen-thawed semen were significantly influenced by the centrifugation regime. Therefore, stallion semen should be centrifuged at 600 x g during 10 minutes before freezing in order to obtain low sperm loss and a good quality of frozen-thawed semen.
authors.affiliation: Nationalgestüt, Avenches. simone.weiss@mbox.haras.admin.ch
authors.forename: S
authors.initials: S
authors.lastname: Weiss
authors.forename: F
authors.initials: F
authors.lastname: Janett
authors.forename: D
authors.initials: D
authors.lastname: Burger
authors.forename: M
authors.initials: M
authors.lastname: Hässig
authors.forename: R
authors.initials: R
authors.lastname: Thun
mesh_terms: D000177:Acrosome / Q000502:physiology; D000818:Animals; D002498:Centrifugation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D015925:Cryopreservation / Q000592:standards / Q000662:veterinary*; D006736:Horses / Q000502:physiology*; D008297:Male; D012661:Semen / Q000166:cytology / Q000502:physiology*; D012662:Semen Preservation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D013075:Sperm Capacitation / Q000502:physiology; D013076:Sperm Count / Q000662:veterinary; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology; D013997:Time Factors