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Lampang, Thailand

Imrat P.,University Utrecht | Mahasawangkul S.,National Elephant Institute | Gosalvez J.,Autonomous University of Madrid | Suthanmapinanth P.,Kasetsart University | And 8 more authors.
Reproduction, Fertility and Development | Year: 2012

Artificial insemination (AI) is a potentially useful tool for breeding captive elephants because it facilitates efforts to minimise inbreeding. However, cooled storage of elephant semen markedly reduces fertility. This study compared the effects on semen-quality parameters, including sperm DNA fragmentation, of storing elephant semen at 48C or 15°C in a commonly-used diluent (TEST) or a diluent developed to protect against sperm DNA damage (BullMax). Storing elephant semen for >24h in either extender at either temperature resulted in decreases in sperm motility, viability, acrosome integrity and DNA integrity (P < 0.05); the decrease inmotility was especially rapid. A subjective impression of circular sperm movement in TEST was confirmed by a higher curvilinear velocity and amplitude of lateral head displacement, but lower straight-line velocity and linearity than in BullMax. Initial percentages of spermatozoa with fragmented DNA (%SDF) did not differ between extenders or temperatures, but the rate of increasein %SDF duringa 48-h incubation at 37°C was higher in TEST than in BullMax (P < 0.05). In conclusion, BullMax allows more linear movement and better preserves DNA stability of stored elephant spermatozoa than TEST. Sperm DNA stability during incubation at 37°C is a promising, discriminative parameter for selecting semen storage conditions of bulls for elephant AI. © CSIRO 2012.

Imrat P.,University Utrecht | Mahasawangkul S.,National Elephant Institute | Thitaram C.,Chiang Mai University | Suthanmapinanth P.,Kasetsart University | And 9 more authors.
Animal Reproduction Science | Year: 2014

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. © 2014 Elsevier B.V.

Thitaram C.,Chiang Mai University | Dejchaisri S.,Kasetsart University | Somgird C.,Chiang Mai University | Angkawanish T.,Elephant Reintroduction Foundation | And 5 more authors.
Applied Animal Behaviour Science | Year: 2015

Captive-held elephants were recruited from several parts of Thailand and released as part of a reintroduction project. Wild elephants with a herd matriarch generally contain the same matrilineal line and are genetically related. However, reintroduced elephants are less likely to be related, but are known to establish social groups. The objective of this study was to investigate the genetic relatedness and behavioral relationships of elephants reintroduced into forested areas in central and northern Thailand. Blood samples were collected from 53 elephants before release into the Sublanka (SLK) and Doi Phamuang (DPM) Wildlife Sanctuaries, and DNA was extracted for microsatellite and mitochondrial analysis. Direct observations of social bonding behaviors were done weekly for 12 months after release, and an association index (AI) calculated for each individual. The results showed a low relatedness for both populations; the observed heterozygosity and number of mitochondrial haplotypes were 0.739 and 13 at SLK (n = 26), and 0.808 and 11 at DPM (n = 27), respectively. Across both locations, 33 elephants formed into 11 groups (range 2-6 individuals/group). The average AI and pairwise genetic relatedness of elephant groups were 0.517 ± 0.039 and 0.078 ± 0.019, respectively, and were not correlated (r = -0.036; p= 0.78). Twenty elephants were not associated with specific groups and had average AI and pairwise genetic relatedness of 0.002 ± 0.001 and 0.047 ± 0.013, respectively, which were not correlated (r= -0.074; p= 0.491). Several mitochondrial haplotypes were found within the same group. Thus, social bonding of the reintroduced elephants was not influenced by genetic relatedness. Rather, groups formed in association with the presence of an elephant calf. Additionally, many elephants occasionally preferred isolation. Thus, reintroduction procedures should favor introducing elephant calves, or adults with calves to increase the chance of group formation and establishment of stable elephant herds. © 2015 Elsevier B.V.

Somgird C.,Chiang Mai University | Sripiboon S.,Chiang Mai University | Sripiboon S.,Kasetsart University | Mahasawangkul S.,National Elephant Institute | And 5 more authors.
Theriogenology | Year: 2015

Bull elephants exhibit marked increases in testosterone secretion during musth, and studies have shown a heightened sensitivity of the testis to GnRH-stimulated testosterone production in musth compared to nonmusth males. However, activity of the hypothalamo-pituitary-gonadal axis before or soon after musth has not been studied in detail. The aim of this study was to evaluate LH and testosterone responses to GnRH challenge in nine adult Asian elephant (Elephas maximus) bulls during three periods relative to musth: premusth, postmusth, and nonmusth. Bulls were administered 80 μg of a GnRH agonist, and blood was collected before and after injection to monitor serum hormone concentrations. The same bulls were injected with saline 2 weeks before each GnRH challenge and monitored using the same blood collection protocol. All bulls responded to GnRH, but not saline, with an increase in LH and testosterone during all three periods. The mean peak LH (1.76 ± 0.19 ng/mL; P < 0.001) and testosterone (6.71 ± 1.62 ng/mL; P = 0.019) concentrations after GnRH were higher than the respective baselines (0.57 ± 0.07 ng/mL, 3.05 ± 0.60 ng/mL). Although basal- and GnRH-induced LH secretion were similar across the stages, evaluation of the area under the curve in GnRH-treated bulls indicated that the testosterone response was greatest during premusth (2.84 ± 0.76 area units; P = 0.019) compared to postmusth (2.02 ± 0.63 area units), and nonmusth (2.01 ± 0.46 area units). This confirms earlier reports that GnRH stimulates LH release and subsequent testosterone production in bull elephants. Furthermore, although the hypothalamo-pituitary-gonadal axis is active throughout the year, the testis appears to be more responsive to LH in terms of testosterone production in the period leading up to musth, compared to the nonmusth and postmusth periods. This heightened sensitivity, perhaps as a result of LH receptor up-regulation, may prime the testis for maximal testosterone production, leading to the physiological and behavioral changes associated with musth. © 2016 Elsevier Inc.

Angkawanish T.,National Elephant Institute | Angkawanish T.,University Utrecht | Wajjwalku W.,Kasetsart University | Sirimalaisuwan A.,Chiang Mai University | And 5 more authors.
Emerging Infectious Diseases | Year: 2010

Four Asian elephants were confirmed to be infected with Mycobacterium tuberculosis by bacterial culture, other diagnostic procedures, and sequencing of 16S-23S rDNA internal transcribed spacer region, 16S rRNA, and gyrase B gene sequences. Genotyping showed that the infectious agents originated from 4 sources in Thailand. To identify infections, a combination of diagnostic assays is essential.

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