Effect of alternate day collection on semen quality of Asian elephants (Elephas maximus) with poor initial fresh semen quality.
In captivity, male Asian elephants often yield poor quality semen after transrectal manually assisted semen collection; however, the reasons for the disappointing semen quality are not clear. Here we test the hypothesis that accumulation of senescent spermatozoa is a contributory factor, and that semen quality can therefore be improved by more frequent ejaculation. To this end we investigated the effect of collecting semen five times on alternate days, after a long period of sexual rest, on semen quality in Asian elephants known to deliver poor semen during infrequent single collections. All eight bulls initially displayed a high incidence of detached sperm heads and low percentages of motile (close to 0%) spermatozoa. After semen collection on alternate days, the percentages of detached sperm heads, and head and mid-piece abnormalities, were reduced significantly (p<0.05). In particular, one bull showed markedly improved sperm motility (increased from 0% to 60%) and membrane integrity (increased from 5% to 75%). In addition, advancing age significantly (p<0.01) correlated with lower percentages of sperm with intact membranes and a higher frequency of detached sperm heads. In contrast to sperm accumulation problems in other species, a small ampullary diameter correlated significantly (p<0.05) with reduced semen quality.
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM, Utrecht, The Netherlands. Electronic address: p_imrat@yahoo.com.
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Imrat
National Elephant Institute, Forest Industry Organization, Lampang 52190, Thailand.
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Mahasawangkul
Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
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Thitaram
Faculty of Veterinary Medicine, Kasetsart University, Nakhonpathom 73140, Thailand.
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Suthanmapinanth
Faculty of Veterinary Medicine, Kasetsart University, Nakhonpathom 73140, Thailand.
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Kornkaewrat
National Elephant Institute, Forest Industry Organization, Lampang 52190, Thailand.
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Sombutputorn
National Elephant Institute, Forest Industry Organization, Lampang 52190, Thailand.
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Jansittiwate
Faculty of Veterinary Medicine, Kasetsart University, Nakhonpathom 73140, Thailand.
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Thongtip
Faculty of Veterinary Medicine, Kasetsart University, Nakhonpathom 73140, Thailand.
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A
Pinyopummin
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM, Utrecht, The Netherlands.
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Colenbrander
Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK.
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Holt
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM, Utrecht, The Netherlands; Department of Production Animal Studies, University of Pretoria, Private Bag X20 Hatfield, Pretoria 0028, South Africa.
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Stout
D000818:Animals; D048430:Cell Shape; D004542:Ejaculation; D004606:Elephants; D008297:Male; D012661:Semen / Q000166:cytology; D055101:Semen Analysis / Q000662:veterinary; D012662:Semen Preservation; D013048:Specimen Handling / Q000379:methods* / Q000662:veterinary; D013077:Sperm Head / Q000473:pathology; D053625:Sperm Retrieval / Q000662:veterinary
Ampullae; Asian elephant; Frequent semen collection; Poor semen quality