title: Liquid storage of equine semen: Assessing the effect of d-penicillamine on longevity of ejaculated and epididymal stallion sperm.
abstract: Short-term storage of equine sperm at 5°C in an extender containing milk and/or egg yolk components is common practice in the equine breeding industry. Sperm motility, viability, DNA integrity and, consequently, fertilizing ability decline over time, partly due to reactive oxygen species (ROS) generation. We investigated whether adding the anti-oxidant d-penicillamine to a commercial milk/egg yolk extender delayed the decrease in semen quality. Semen was recovered on four consecutive days from eight 3-year old Warmblood stallions. On day 5, seven of the stallions were castrated and sperm recovered from the caudae epididymides. Ejaculated samples were split, and one portion was centrifuged and re-suspended to reduce seminal plasma content. All samples were diluted to 50millionsperm/ml and divided into two portions, one of which was supplemented with 0.5mM d-penicillamine. After 48h, 96h, 144h and 192h storage, sperm motility was assessed by computer-assisted semen analysis (CASA), viability by SYBR14/PI staining, and DNA integrity using the sperm chromatin structure assay (SCSA). d-Penicillamine had no effect on motility of ejaculated sperm (P>0.05) but reduced total and progressive motility of epididymal sperm. Sperm chromatin integrity was not influenced by storage time, seminal plasma or d-penicillamine. In short, adding d-penicillamine to a commercial semen extender was neither beneficial nor detrimental to the maintenance of quality in ejaculated semen stored at 5°C. The negative effect on motility of epididymal sperm may reflect differences in (membrane) physiology of spermatozoa that have not been exposed to seminal plasma.
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands. Electronic address: P.T.Brogan@uu.nl.
authors.forename: P T
authors.initials: PT
authors.lastname: Brogan
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands. Electronic address: M.M.Beitsma@uu.nl.
authors.forename: M
authors.initials: M
authors.lastname: Beitsma
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands. Electronic address: H.H.W.Henning@uu.nl.
authors.forename: H
authors.initials: H
authors.lastname: Henning
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CM Utrecht, The Netherlands; Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands. Electronic address: B.M.Gadella@uu.nl.
authors.forename: B M
authors.initials: BM
authors.lastname: Gadella
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands; Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CM Utrecht, The Netherlands; Section of Reproduction, Faculty of Veterinary Science, University of Pretoria, Private Bag XO4, Onderstepoort 0110, South Africa. Electronic address: T.A.E.Stout@uu.nl.
authors.forename: T A E
authors.initials: TA
authors.lastname: Stout
mesh_terms: D000818:Animals; D004542:Ejaculation; D004822:Epididymis; D006736:Horses / Q000502:physiology; D008297:Male; D010396:Penicillamine / Q000494:pharmacology*; D012661:Semen / Q000187:drug effects; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*
chemical_list: D010396:Penicillamine
keywords: Antioxidant; Chilled semen; Chromatin; ROS; SCSA