Collection and preservation of pygmy hippopotamus (Choeropsis liberiensis) semen.
Knowledge about the reproduction of the endangered pygmy hippopotamus is almost non-existent. This study takes the first step toward changing this by devising a protocol for the collection, evaluation, and short-term preservation of semen of this endangered species. Semen was collected successfully from seven bulls by electroejaculation, using a specially designed rectal probe. Mean +/- SEM values of native sperm parameters from combined best fractions were: motility-80.0 +/- 4.1%, concentration-2421 +/- 1530 x 10(6) cells/mL, total collected cell number-759 +/- 261 x 10(6) cells, intact acrosome-87.8 +/- 1.2%, intact morphology-52.7 +/- 4.3%, and, for some, hypoosmotic swelling test-79.3 +/- 4.4% and seminal plasma osmolarity-297.5 +/- 3.3 mOsm. Seven different extenders were tested for sperm storage under chilling conditions: Berliner Cryomedium (BC), Biladyl, modification of Kenney modified Tyrode's medium (KMT), MES medium, Androhep((R)), boar M III() extender and Human Sperm Refrigeration Medium. While differences between males were apparent, the BC was consistently superior to all other extenders in sperm motility and facilitated storage for 7 d with up to 30% motility and some motility even after 3 weeks. With this knowledge in hand, the obvious two directions for future research are to conduct artificial insemination and to develop a technique for sperm cryopreservation.
Saragusty
J
J
Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, D-10315 Berlin, Germany. Saragusty@izw-berlin.de
Hildebrandt
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Göritz
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D000177:Acrosome; D000818:Animals; D003247:Conservation of Natural Resources; D015925:Cryopreservation; D003451:Cryoprotective Agents; D056727:Endangered Species; D008297:Male; D008322:Mammals / Q000502:physiology*; D012661:Semen / Q000166:cytology / Q000502:physiology; D012662:Semen Preservation; D013081:Sperm Motility
D003451:Cryoprotective Agents