title: Characteristics of high-quality Asian elephant (Elephas maximus) ejaculates and in vitro sperm quality after prolonged chilled storage and directional freezing.
abstract: The in vitro quality of spermatozoa from one elephant (Elephas maximus) was examined after chilled storage and directional freezing (DF). High-quality, non-contaminated ejaculates (77.6±6.0% progressive motility, 3.9±1.5 µg creatinine mL(-1) raw semen, 2.7±0.6% detached heads) were cryopreserved after 0 (0hStor), 12 (12hStor) and 24 h (24hStor) of chilled storage. At 0 h and 6h post-thawing, total motility, plasma membrane integrity, acrosome integrity, mitochondrial activity and normal morphology were similar (P>0.05) across treatments. In contrast, progressive motility, rapid velocity and several kinematic parameters were lower (P<0.05) for 24Stor compared with 0hStor at 0 h post-thaw. By 6 h post-thaw, amplitude of lateral head displacement and velocity parameters (average pathway, straight-line and curvilinear velocity) were lower (P<0.05) for 24hStor compared with 0hStor and 12hStor. DNA integrity was high and remained unchanged (P>0.05) across all groups and processing stages (1.6±0.6% of cells contained fragmented DNA). Results indicate that DF after up to 12 h of chilled storage results in a post-thaw sperm population of acceptable quality for artificial insemination. These findings have implications for the cryopreservation of sex-sorted spermatozoa, which typically undergo more than 12 h of chilled storage prior to sorting and preservation.
authors.affiliation: SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, San Diego, CA 92109, USA. justine.obrien@seaworld.com
authors.forename: J K
authors.initials: JK
authors.lastname: O'Brien
authors.forename: K J
authors.initials: KJ
authors.lastname: Steinman
authors.forename: G A
authors.initials: GA
authors.lastname: Montano
authors.forename: C C
authors.initials: CC
authors.lastname: Love
authors.forename: R L
authors.initials: RL
authors.lastname: Saiers
authors.forename: T R
authors.initials: TR
authors.lastname: Robeck
mesh_terms: D000177:Acrosome / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D003404:Creatinine / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004606:Elephants; D008297:Male; D055101:Semen Analysis / Q000662:veterinary*; D013081:Sperm Motility / Q000502:physiology; D013997:Time Factors
chemical_list: D003404:Creatinine