Characterization of semen collected from beagles and captive japanese black bears ( )

Kojima, Eigo; Tsuruga, Hifumi; Komatsu, Takeshi; Murase, Tetsuma; Tsubota, Toshio; Kita, Isao

doi:10.1016/s0093-691x(01)00439-3

Cited by 32 publications

(44 citation statements)

References 18 publications

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“…The reported sperm concentration of the captive Japanese black bear (mean 361 × 10 6 /ml [16]), Hokkaido brown bear (mean 590 × 10 6 /ml [13]) and Giant panda (mean 645 × 10 6 /ml [22]) was similar to that observed in this study (mean 540 × 10 6 /ml). On the other hand, the reported total ejaculate volume of the captive Japanese black bear (mean 0.2 ml [16]), Hokkaido brown bear (mean 3.7 ml [13]), Giant panda (mean 6.5 ml [22]) and free-ranging Japanese black bear (mean 1.5 ml; this study) differed from each other to some extent.…”

Section: Fresh Semensupporting

confidence: 87%

“…Semen examination and cryopreservation: Examination and cryopreservation of semen was performed according to the method that we used in dogs [16] with some modifications. Briefly, when more than one tube of semen sample was collected during one anesthesia period, each was analyzed.…”

Section: Capture and Handlingmentioning

confidence: 99%

“…In recent years, their habitats have become fragmented and shrunken by human activity, and this species even faces extinction in some areas [7]. What is worse, bears have been killed to protect forestry, agriculture, livestock and humans from damage caused by them.Endangered and threatened wild animals are now attracting attention as a genetic resource and for species conservation, and semen has been recovered from various captive non-domestic animals, including fat-tailed dunnarts, koalas, brushtail possums, long-footed potoroos, northern brown bandicoots and ring-tailed possums [32] [4,20,22,24], Hokkaido brown bears [13,14] and Japanese black bears [16]. However, these studies were done with captive animals, and there are no reports on semen collection and cryopreservation in free-ranging bears.…”

mentioning

confidence: 99%

“…As to Ursidae, there are reports on electroejaculation and/or semen cryopreservation in giant pandas [4,20,22,24], Hokkaido brown bears [13,14] and Japanese black bears [16]. However, these studies were done with captive animals, and there are no reports on semen collection and cryopreservation in free-ranging bears.…”

mentioning

confidence: 99%

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Electroejaculation and Semen Cryopreservation of Free-Ranging Japanese Black Bears (Ursus thibetanus japonicus)

Okano

Murase

Tsubota

2004

The Journal of Veterinary Medical Science

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ABSTRACT. The Japanese black bear (Ursus thibetanus japonicus) is endangered for extinction in some areas of Japan, and semen collection and cryopreservation are an important means to preserve genetic resources. The aim of this study was to characterize and c ryopreserve semen of free-ranging Japanese black bears. Semen was collected by electroejaculation procedure from 4 free-ranging Japanese black bears at the capture point in the field. Ejaculates containing motile sperm were recovered from all of the animals and ejaculate volume, total sperm count, % motility (percentage of motile spermatozoa), % viability (percentage of spermatozoa that excluded eosin) and % abnormal morphology (range (mean)) were 0.65-2.20 (1.51) ml, 99-1082 (490) × 10 6 , 5-100 (31), 42-97 (66) and 20-87 (53), respectively. Three of the 4 ejaculates were diluted with an egg yolk-TRIS-citrate-glucose extender and cryopreserved in liquid nitrogen. Motile spermatozoa were observed after freezing and thawing in all cases. This study showed that electroejaculation would be a useful method for collecting semen from free-ranging Japanese black bears and that at least motile spermatozoa would be obtained by fre ezing the thus collected electroejaculates. KEY WORDS: cryopreservation, electroejaculation, free-ranging, Japanese black bear, semen.J. Vet. Med. Sci. 66(11): 1371-1376, 2004 The Japanese black bear (Ursus thibetanus japonicus) is a large mammal that inhabits the islands of Honshu and Shikoku in Japan. In recent years, their habitats have become fragmented and shrunken by human activity, and this species even faces extinction in some areas [7]. What is worse, bears have been killed to protect forestry, agriculture, livestock and humans from damage caused by them.Endangered and threatened wild animals are now attracting attention as a genetic resource and for species conservation, and semen has been recovered from various captive non-domestic animals, including fat-tailed dunnarts, koalas, brushtail possums, long-footed potoroos, northern brown bandicoots and ring-tailed possums [32] [4,20,22,24], Hokkaido brown bears [13,14] and Japanese black bears [16]. However, these studies were done with captive animals, and there are no reports on semen collection and cryopreservation in free-ranging bears. Cryopreservation of semen collected from free-ranging animals is one of the most important methods for preservation of genetic resources and useful for artificial breeding. Moreover, characteristics of semen from wild animals may be essential for understanding reproductive status under field conditions, although studies using captive animals, kept under controlled conditions, may provide valuable data to analogize state under field conditions. It is easy to expect that the state of captive animals may differ from that of free-ranging ones to some extent, because of differences in their living environment and diet. It is difficult to obtain semen from free-ranging Japanese black bears due to limited access to the animals and seasonality of their ...

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Section: Fresh Semensupporting

confidence: 87%

Section: Capture and Handlingmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Electroejaculation and Semen Cryopreservation of Free-Ranging Japanese Black Bears (Ursus thibetanus japonicus)

Okano

Murase

Tsubota

2004

The Journal of Veterinary Medical Science

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“…Semen was diluted with physiological saline, and mixed with an equal volume of 2% glutaraldehyde in 0.165 M sodium cacodylate buffer (pH 7.0). The fixed samples were examined under a light microscope and spermatozoa with a dense apical ridge of the head were considered acrosome-intact [12,15,24]. Proportions of spermatozoa with intact acrosomes were obtained (percentage of acrosome-intact spermatozoa) (except for Experiment 1).…”

Section: Methodsmentioning

confidence: 99%

Effects of Final Dilution Rate, Sperm Concentration and Times for Cooling and Glycerol Equilibration on Post-Thaw Characteristics of Canine Spermatozoa

Okano

Murase

Asano

et al. 2004

The Journal of Veterinary Medical Science

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ABSTRACT. This study re-evaluated a protocol for cryopreservation of canine semen. Semen from 4 beagle dogs was pooled, concentrated by centrifugation and adjusted to increasing sperm concentrations by adding back seminal plasma. The prepared or original semen was diluted with an extender (Egg yolk-Tris-citrate-glucose) and cooled to 4°C (cooling), followed by a second dilution with the same extender including glycerol, equilibrated at 4°C (equilibration), then stored in liquid nitrogen. The semen was diluted for frozen samples having a fixed sperm concentration with increasing dilution rates or for those having the reverse combinations. Various dilution rates of 2.5-10 folds or sperm concentrations of 0.25-2.5 × 10 8 /ml had no significant effect on post-thaw sperm characteristics. When cooling was done for different times (0-26 hr) with glycerol equilibration for 1 hr, post-thaw characteristics were better at 2 and 3 hr of cooling, while various times for equilibration (0-4 hr) with cooling for 3 hr had no effect. These results suggest that different dilution rates and sperm concentrations within the ranges tested may not affect the post-thaw sperm characterisitics and that sufficient time for cooling may be essential but a specific equilibration time may not necessarily be required. KEY WORDS: artificial insemination, canine, cryopreservation, semen, spermatozoa.J. Vet. Med. Sci. 66(11): 1359-1364, 2004 Biotechnological studies may contribute much to the conservation of endangered wildlife species, and assisted reproduction techniques in domestic dogs may be applicable to non-domesticated canid species [11,14]. Indeed, techniques of sperm cryopreservation developed for domestic dogs have been applied to captive red wolves [10]. On the other hand, if semen were collected from wild animals in the field, manipulation of the ejaculate would have to be carried out under unfavorable conditions. Thus, modifications would be needed for the application of techniques developed for dogs to wild animals.Successful artificial insemination with frozen canine semen has been well documented [18,22,23,25,27] since the first conception was reported by Seager [21], and recently, the freezing protocol for canine semen has been improved [1,3,20,[28][29][30]. If semen is diluted to a constant final sperm concentration, the dilution rates may differ. Alternatively, if the dilution rate is fixed, the final sperm concentration might fluctuate according to the sperm concentration measured in the collected semen. Systematic studies examining the effects of the final dilution rate and the final sperm concentration on post-thaw sperm characteristics are lacking, except for limited information provided by Peña and Linde-Forsberg [17].In most cases, canine semen is diluted, equilibrated with a cryoprotectant such as glycerol, and stored frozen in liquid nitrogen. In some reports, collected semen is directly diluted with an extender including glycerol and then equilibrated for hours before freezing [1,7,9,13,18,20,23,26].In other reports, s...

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Effects on brown bear (Ursus arctos) spermatozoa freezability of different extender and dilution ratios used for pre-freezing centrifugation

et al. 2010

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The objective of this study was to determine how the extender and dilution ratio used during centrifugation affect bear spermatozoa quality before and after freezingthawing. Semen was collected from 15 brown bears by electroejaculation. In experiment 1, semen was divided into five aliquots and diluted using one of the following extenders: Tris-citric-glucose (TCG), Tris-citric-glucose-3% BSA, Tris-citric-glucose-1% egg yolk or CaninePro. In experiment 2, semen was divided into five aliquots and diluted 1:1, 1:4, 1:8 or 1:16 (semen:extender) with Triscitric-glucose. In both experiments, one aliquot was left undiluted and it was used as a control. All the aliquots were centrifuged at 600×g for 6 min and frozen. Samples were analysed by post-thawing for motility (CASA) and, by flow cytometry, for viability (YO-PRO-1), acrosomal status (PNA-FITC/PI) and mitochondrial status (JC-1). CaninePro rendered the highest motility with respect to the undiluted control (total motility, 53.1% vs. 38.5%, P<0.001), and CaninePro and TCG significantly increased the percentage of viable and acrosome-intact spermatozoa (43.2 and 43.4, respectively, vs. 39.4, P<0.05). In experiment 2, dilution 1:4 yielded the highest value of total motility (78.8 vs. 67.2, P<0.05) and proportion of spermatozoa with intact membrane and acrosome (64.5 vs. 54.4, P<0.01). In general, diluting 1:4 or 1:8 brown bear semen prior to centrifugation improved the motility and acrosome status of the thawed spermatozoa.

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Characterization of semen collected from beagles and captive japanese black bears ( )

Cited by 32 publications

References 18 publications

Electroejaculation and Semen Cryopreservation of Free-Ranging Japanese Black Bears (Ursus thibetanus japonicus)

Electroejaculation and Semen Cryopreservation of Free-Ranging Japanese Black Bears (Ursus thibetanus japonicus)

Effects of Final Dilution Rate, Sperm Concentration and Times for Cooling and Glycerol Equilibration on Post-Thaw Characteristics of Canine Spermatozoa

Effects on brown bear (Ursus arctos) spermatozoa freezability of different extender and dilution ratios used for pre-freezing centrifugation

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