title: Effect of pre-freeze semen quality, extender and cryoprotectant on the post-thaw quality of Asian elephant (Elephas maximus indicus) semen.
abstract: Semen cryopreservation and artificial insemination (AI) are potentially valuable methods for supporting the breeding management of endangered species like the Asian elephant. Cryopreservation of Asian elephant semen has however proven problematic with respect to maintenance of both adequate semen quality and fertility post-thaw. In this study, nine ejaculates from three adult bulls were used to compare the influence of extender (TEST versus INRA96®) and penetrating cryoprotectants (3% glycerol, 5% glycerol and 4% methylformamide) on post-thaw semen quality. We demonstrate that not only the freezing process, but also the quality of the semen before freezing, significantly influences the freezability of Asian elephant semen. Pre-freeze motility, viability, semen volume, semen pH, sperm concentration and the incidence of sperm mid-piece and tail abnormalities all significantly (p<0.05) affected post-thaw semen quality. While extender and cryoprotectant did not significantly affect any of the above semen quality parameters post-thaw, the skim-milk based extender (INRA96®) preserved DNA integrity better (p<0.05) than the egg yolk extender (TEST). Considerable between-ejaculate variation in all post-thaw semen quality parameters was also noted. It is concluded that strict criteria for semen quality is essential for the selection of Asian elephant bull ejaculates suitable for cryopreservation; stricter initial selection should improve the mean post-thaw quality.
authors.affiliation: Faculty of Veterinary Medicine, Department of Equine Sciences, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands. p_imrat@yahoo.com
authors.forename: P
authors.initials: P
authors.lastname: Imrat
authors.forename: P
authors.initials: P
authors.lastname: Suthanmapinanth
authors.forename: K
authors.initials: K
authors.lastname: Saikhun
authors.forename: S
authors.initials: S
authors.lastname: Mahasawangkul
authors.forename: E
authors.initials: E
authors.lastname: Sostaric
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: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000378:metabolism*; D004606:Elephants / Q000502:physiology*; D005559:Formamides / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D008297:Male; D012661:Semen / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D055101:Semen Analysis; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility
chemical_list: D003451:Cryoprotective Agents; D005559:Formamides; D005990:Glycerol; C002950:methylformamide