title: Sperm rescue in wild African elephants.
abstract: This study investigated ways of improving the usefulness of ~1700 mL of poor-quality frozen semen collected from wild African elephant (Loxodonta africana) bulls. Ten semen samples from six bulls, frozen with 5% glycerol in Berliner cryomedium, with or without prior removal of the seminal plasma by centrifugation, were tested. All samples were subjected to the following density-gradient centrifugation treatments: no centrifugation (control), sham centrifugation, Percoll, OptiPrep, Isolate and PureSperm. Sample evaluation included motility, concentration, viability, acrosome integrity and normal morphology after thawing and after gradient centrifugation. Motility was also evaluated 3 h after thawing. While all treatments were similar to the Control in acrosome integrity and normal morphology, significant differences were noted in concentration, viability and motility. Samples treated by Percoll showed the best motility, which was maintained unchanged over 3 h of incubation (37°C). Correlations between manual and automated evaluations of concentration were high (cytometer; rho = 0.92), but were lower for viability (cytometer; rho = 0.57) and motility (computer-aided sperm analysis; rho = 0.66). By performing density centrifugation, the quality of these sperm samples may be improved to a level suitable for artificial insemination in elephants. Although a sizeable proportion of cells are lost in the process, combining samples may still allow for multiple inseminations.
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, D-10315 Berlin, Germany.|Corresponding author. Email: saragusty@izw-berlin.de.
authors.forename: Joseph
authors.initials: J
authors.lastname: Saragusty
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, D-10315 Berlin, Germany.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Prieto
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, D-10315 Berlin, Germany.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Courtiol
authors.affiliation: ZooParc de Beauval, 41110 Saint Aignan s/ Cher, France.|Present address: FauneVet, CHV Atlantia, 22 rue René Viviani, 44200 Nantes, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Potier
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, D-10315 Berlin, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Göritz
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, D-10315 Berlin, Germany.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Hildebrandt
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, D-10315 Berlin, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Hermes
keywords: conservation; cryopreservation; directional freezing; endangered; spermatozoa