title: Effect of cooled storage on quality and DNA integrity of Asian elephant (Elephas maximus) spermatozoa.
abstract: Artificial insemination (AI) is a potentially useful tool for breeding captive elephants because it facilitates efforts to minimise inbreeding. However, cooled storage of elephant semen markedly reduces fertility. This study compared the effects on semen-quality parameters, including sperm DNA fragmentation, of storing elephant semen at 4°C or 15°C in a commonly-used diluent (TEST) or a diluent developed to protect against sperm DNA damage (BullMax). Storing elephant semen for >24 h in either extender at either temperature resulted in decreases in sperm motility, viability, acrosome integrity and DNA integrity (P < 0.05); the decrease in motility was especially rapid. A subjective impression of circular sperm movement in TEST was confirmed by a higher curvilinear velocity and amplitude of lateral head displacement, but lower straight-line velocity and linearity than in BullMax. Initial percentages of spermatozoa with fragmented DNA (%SDF) did not differ between extenders or temperatures, but the rate of increase in %SDF during a 48-h incubation at 37°C was higher in TEST than in BullMax (P < 0.05). In conclusion, BullMax allows more linear movement and better preserves DNA stability of stored elephant spermatozoa than TEST. Sperm DNA stability during incubation at 37°C is a promising, discriminative parameter for selecting semen storage conditions of bulls for elephant AI.
authors.affiliation: Faculty of Veterinary Medicine, Department of Equine Sciences, Utrecht University, Yalelaan 114, 3584CM, Utrecht, The Netherlands. p.imrat@uu.nl
authors.forename: P
authors.initials: P
authors.lastname: Imrat
authors.forename: S
authors.initials: S
authors.lastname: Mahasawangkul
authors.forename: J
authors.initials: J
authors.lastname: Gosálvez
authors.forename: P
authors.initials: P
authors.lastname: Suthanmapinanth
authors.forename: P
authors.initials: P
authors.lastname: Sombutputorn
authors.forename: S
authors.initials: S
authors.lastname: Jansittiwate
authors.forename: N
authors.initials: N
authors.lastname: Thongtip
authors.forename: A
authors.initials: A
authors.lastname: Pinyopummin
authors.forename: B
authors.initials: B
authors.lastname: Colenbrander
authors.forename: W V
authors.initials: WV
authors.lastname: Holt
authors.forename: T A E
authors.initials: TA
authors.lastname: Stout
mesh_terms: D000177:Acrosome; D000818:Animals; D001947:Breeding; D002470:Cell Survival; D003080:Cold Temperature; D004249:DNA Damage / Q000502:physiology*; D053938:DNA Fragmentation; D004606:Elephants / Q000502:physiology*; D005298:Fertility; D007315:Insemination, Artificial / Q000662:veterinary; D008297:Male; D055101:Semen Analysis / Q000662:veterinary; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D013997:Time Factors