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Towiboon P, Saenphet K, Tayapiwattana C, Tangyuenyong S, Watanabe G, Mahasawangkul S, Brown JL, Thitaram C. Relationship among Serum Progestagens, Cortisol, and Prolactin in Pregnant and Cycling Asian Elephants in Thailand. Vet Sci 2022; 9:vetsci9050244. [PMID: 35622772 PMCID: PMC9144649 DOI: 10.3390/vetsci9050244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/16/2022] [Accepted: 05/20/2022] [Indexed: 12/05/2022] Open
Abstract
The aim of this study was to examine relationships among serum progestagens, cortisol, and prolactin in pregnant and normal cycling Asian elephants living in tourist camps in northern Thailand. Samples were collected twice a month for 22 months from nine elephants. Of those, four were pregnant (24.3 ± 2.9 years of age; range 21−28 years) and five (20.2 ± 9.6 years; range 8−34 years) exhibited normal ovarian cycles based on serum progestagen analyses. Gestation was divided into three periods: 1st (week 1−31), 2nd (week 32−62), and 3rd (week 63 to parturition), while the estrous cycle was divided into the follicular and luteal phases. Serum progestagens were higher during the luteal phase of the cycle (p < 0.003), whereas cortisol and prolactin were similar. In pregnant elephants, there were no differences in serum progestagens or cortisol concentrations across the three gestational periods, whereas prolactin concentrations increased significantly during the 2nd and 3rd periods (p < 0.0001). By contrast, prolactin concentrations in nonpregnant elephants were consistently low throughout the ovarian cycle. In one cycling female, prolactin concentrations were similar to pregnant elephants, perhaps because she was an allomother to two calves. Another cycling female exhibited consistently elevated cortisol concentrations, 5 to 10 times higher than the other elephants. There were no correlations between serum progestagens, cortisol, and prolactin throughout gestation; however, serum progestagens and cortisol were positively related in cycling elephants (r = 0.386, p < 0.001). From our results, there were a number of individual differences in reproductive hormonal patterns, so it is important to develop personalized monitoring programs for each elephant to enhance breeding success and create sustaining captive populations of elephants in Asia.
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Affiliation(s)
- Patcharapa Towiboon
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; (P.T.); (K.S.)
- Center of Elephant and Wildlife Health, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Kanokporn Saenphet
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; (P.T.); (K.S.)
| | - Chatchai Tayapiwattana
- Center of Biomolecular Therapy and Diagnosis, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Siriwan Tangyuenyong
- Department of Companion Animals and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand;
- Animal Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan;
| | - Gen Watanabe
- Animal Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan;
| | - Sittidet Mahasawangkul
- Thai Elephant Conservation Center, National Elephant Institute, Forest Industry Organization, Lampang 52190, Thailand;
| | - Janine L. Brown
- Center of Elephant and Wildlife Health, Chiang Mai University, Chiang Mai 50200, Thailand;
- Center for Species Survival, Smithsonian National Zoo Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Chatchote Thitaram
- Center of Elephant and Wildlife Health, Chiang Mai University, Chiang Mai 50200, Thailand;
- Animal Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan;
- Correspondence:
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Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants ( Loxodonta africana). Animals (Basel) 2021; 11:ani11123525. [PMID: 34944300 PMCID: PMC8698154 DOI: 10.3390/ani11123525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/10/2021] [Accepted: 12/07/2021] [Indexed: 12/04/2022] Open
Abstract
Simple Summary Regular training for medical or enrichment purposes and the provision of environmental enrichment, such as varied feeding schedules and novel objects, are part of the management of African elephants in zoos. The present study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal. We found high salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. Moreover, males and young elephants showed lower salivary cortisol levels than females and old elephants, respectively. The zoo, handling method (free vs. protected contact to keepers), reproductive and social status, however, did not influence the salivary cortisol levels of the animals studied. We conclude that the relatively high cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed cortisol increase. In addition, understanding why animals differ in stress responses will help to manage stress in zoo elephants with the goal of ensuring their welfare. Abstract Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.
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Glaeser SS, Edwards KL, Wielebnowski N, Brown JL. Effects of physiological changes and social life events on adrenal glucocorticoid activity in female zoo-housed Asian elephants (Elephas maximus). PLoS One 2020; 15:e0241910. [PMID: 33156856 PMCID: PMC7647113 DOI: 10.1371/journal.pone.0241910] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 10/22/2020] [Indexed: 11/25/2022] Open
Abstract
Ensuring good health and welfare is an increasingly important consideration for conservation of endangered species and includes breeding of individuals managed under human care. Understanding how factors in the captive environment affect individual animal wellbeing can be aided by long-term monitoring of biological functioning. This study involved longitudinal assessments (4 to 28 years) of reproductive and adrenal hormones in zoo-housed female Asian elephants (Elephas maximus) (age range 4 to ~71 years) to elucidate patterns in adrenal glucocorticoid (GC) activity in association with reproductive and demographic factors, and examine individual response to major social changes. Concentrations of serum and urinary cortisol covaried more consistently with physiological changes (ovarian cycle phase, puberty, pregnancy, lactational anestrus, and age) than with social life events (births, deaths, and facility transfers). Cortisol fluctuated across the ovarian cycle with mean concentrations being higher in the follicular than in the luteal phase, and concentrations were highest in lactational anestrous compared to all other reproductive states. The elephants in this study exhibited substantial individuality in adrenal GC response to major social change, reinforcing the need to assess welfare on an individual basis and to consider factors influencing the impact of perceived stressors, such as social relationships, social support, temperament, and life history. Outcomes from this study deepen our understanding of Asian elephant physiology and highlight the importance of taking intrinsic patterns of hormone secretion into account when evaluating the impact of external factors. Finally, a better understanding of the impact of social change and resiliency in response to real and perceived stressors allows us to improve social management to enhance welfare in both captive settings and free-ranging environments.
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Affiliation(s)
| | - Katie L. Edwards
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
- North of England Zoological Society, Chester Zoo, Upton-by-Chester, United Kingdom
| | | | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Smithsonian National Zoological Park, Front Royal, Virginia, United States of America
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Robertson JK, Mastromonaco GF, Burness G. Social hierarchy reveals thermoregulatory trade-offs in response to repeated stressors. J Exp Biol 2020; 223:jeb229047. [PMID: 32967999 DOI: 10.1242/jeb.229047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/09/2020] [Indexed: 11/20/2022]
Abstract
Coping with stressors can require substantial energetic investment, and when resources are limited, such investment can preclude simultaneous expenditure on other biological processes. Among endotherms, energetic demands of thermoregulation can also be immense, yet our understanding of whether a stress response is sufficient to induce changes in thermoregulatory investment is limited. Using the black-capped chickadee as a model species, we tested a hypothesis that stress-induced changes in surface temperature (Ts), a well-documented phenomenon across vertebrates, stem from trade-offs between thermoregulation and stress responsiveness. Because social subordination is known to constrain access to resources in this species, we predicted that Ts and dry heat loss of social subordinates, but not social dominants, would fall under stress exposure at low ambient temperatures (Ta), and rise under stress exposure at high Ta, thus permitting a reduction in total energetic expenditure toward thermoregulation. To test our predictions, we exposed four social groups of chickadees to repeated stressors and control conditions across a Ta gradient (n=30 days/treatment/group), whilst remotely monitoring social interactions and Ts Supporting our hypothesis, we show that: (1) social subordinates (n=12), who fed less than social dominants and alone experienced stress-induced mass-loss, displayed significantly larger changes in Ts following stress exposure than social dominants (n=8), and (2) stress-induced changes in Ts significantly increased heat conservation at low Ta and heat dissipation at high Ta among social subordinates alone. These results suggest that chickadees adjust their thermoregulatory strategies during stress exposure when resources are limited by ecologically relevant processes.
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Affiliation(s)
- Joshua K Robertson
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada K9L 0G2
- Department of Wildlife and Science, Toronto Zoo, Scarborough, ON, Canada M1B 5K7
| | | | - Gary Burness
- Department of Biology, Trent University, Peterborough, ON, Canada K9L 0G2
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Paudel S, Brown JL, Thapaliya S, Dhakal IP, Mikota SK, Gairhe KP, Shimozuru M, Tsubota T. Comparison of cortisol and thyroid hormones between tuberculosis-suspect and healthy elephants of Nepal. J Vet Med Sci 2016; 78:1713-1716. [PMID: 27452878 PMCID: PMC5138427 DOI: 10.1292/jvms.16-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We compared cortisol and thyroid hormone (T3 and T4) concentrations between tuberculosis
(TB)-suspected (n=10) and healthy (n=10) elephants of Nepal. Whole blood was collected
from captive elephants throughout Nepal, and TB testing was performed using the ElephantTB
STAT-PAK® and DPP VetTB® serological assays that detect antibodies
against Mycobacterium tuberculosis and M. bovis in
elephant serum. Cortisol, T3 and T4 were quantified by competitive enzyme immunoassays,
and the results showed no significant differences in hormone concentrations between
TB-suspect and healthy elephants. These preliminary data suggest neither adrenal nor
thyroid function is altered by TB disease status. However, more elephants, including those
positively diagnosed for TB by trunk wash cultures, need to be evaluated over time to
confirm results.
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Affiliation(s)
- Sarad Paudel
- Laboratory of Wildlife Biology and Medicine, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
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Fanson KV, Keeley T, Fanson BG. Cyclic changes in cortisol across the estrous cycle in parous and nulliparous Asian elephants. Endocr Connect 2014; 3:57-66. [PMID: 24623735 PMCID: PMC3987288 DOI: 10.1530/ec-14-0025] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the context of reproduction, glucocorticoids (GCs) are generally considered to have negative effects. However, in well-studied model species, GCs fluctuate predictability across the estrous cycles, and short-term increases promote healthy ovarian function. Reproductive challenges have plagued captive elephant populations, which are not currently self-sustaining. Efforts to understand reproductive dysfunction in elephants have focused on the suppressive effects of cortisol, but the potential permissive or stimulatory effects of cortisol are unknown. In this study, we provide a detailed examination of cortisol patterns across the estrous cycle in Asian elephants (Elephas maximus). Time series analysis was used to analyze cortisol and progesterone data for a total of 73 cycles from eight females. We also compared cortisol profiles between females that successfully conceived and females that failed to conceive despite repeated mating attempts. Our results revealed that cortisol fluctuates predictably across the estrous cycle, with a peak during the second half of the follicular phase followed by low levels throughout the luteal phase. Furthermore, this pattern was significantly altered in nulliparous females; cortisol concentrations did not decline during the luteal phase to the same extent as in parous females. This study highlights the complexity of cortisol signaling and suggests future directions for understanding the role of cortisol in reproductive dysfunction.
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Affiliation(s)
- Kerry V Fanson
- Wildlife Reproductive Centre, Taronga Conservation Society AustraliaDubbo, New South WalesAustralia
- School of Life and Environmental Sciences, Deakin University75 Pigdons Road, Waurn Ponds, Victoria, 3217Australia
- Correspondence should be addressed to K V Fanson
| | - Tamara Keeley
- Wildlife Reproductive Centre, Taronga Conservation Society AustraliaDubbo, New South WalesAustralia
- School of Agriculture and Food Sciences, University of QueenslandGatton, QueenslandAustralia
| | - Benjamin G Fanson
- School of Life and Environmental Sciences, Deakin University75 Pigdons Road, Waurn Ponds, Victoria, 3217Australia
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HILDEBRANDT TB, LUEDERS I, HERMES R, GOERITZ F, SARAGUSTY J. Anatomical, Physiological, Behavioral and Pathological Aspects of the Estrous Cycle in Elephants. ACTA ACUST UNITED AC 2012. [DOI: 10.5686/jjzwm.17.97] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Thomas B HILDEBRANDT
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Imke LUEDERS
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Robert HERMES
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Frank GOERITZ
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Joseph SARAGUSTY
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
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Benavides Valades G, Ganswindt A, Annandale H, Schulman ML, Bertschinger HJ. Non-invasive assessment of the reproductive cycle in free-ranging female African elephants (Loxodonta africana) treated with a gonadotropin-releasing hormone (GnRH) vaccine for inducing anoestrus. Reprod Biol Endocrinol 2012; 10:63. [PMID: 22921012 PMCID: PMC3485135 DOI: 10.1186/1477-7827-10-63] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/21/2012] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND In southern Africa, various options to manage elephant populations are being considered. Immunocontraception is considered to be the most ethically acceptable and logistically feasible method for control of smaller and confined populations. In this regard, the use of gonadotropin-releasing hormone (GnRH) vaccine has not been investigated in female elephants, although it has been reported to be safe and effective in several domestic and wildlife species. The aims of this study were to monitor the oestrous cycles of free-ranging African elephant cows using faecal progestagen metabolites and to evaluate the efficacy of a GnRH vaccine to induce anoestrus in treated cows. METHODS Between May 2009-June 2010, luteal activity of 12 elephant cows was monitored non-invasively using an enzyme immunoassay detecting faecal 5alpha-reduced pregnanes (faecal progestagen metabolites, FPM) on a private game reserve in South Africa. No bulls of breeding age were present on the reserve prior to and for the duration of the study. After a 3-month control period, 8 randomly-selected females were treated twice with 600 micrograms of GnRH vaccine (Improvac®, Pfizer Animal Health, Sandton, South Africa) 5-7 weeks apart. Four of these females had been treated previously with the porcine zona pellucida (pZP) vaccine for four years (2004-2007). RESULTS All 12 monitored females (8 treated and 4 controls) showed signs of luteal activity as evidenced by FPM concentrations exceeding individual baseline values more than once. A total of 16 oestrous cycles could be identified in 8 cows with four of these within the 13 to 17 weeks range previously reported for captive African elephants. According to the FPM concentrations the GnRH vaccine was unable to induce anoestrus in the treated cows. Overall FPM levels in samples collected during the wet season (mean 4.03 micrograms/gram dry faeces) were significantly higher (P<0.002) than the dry season (mean 2.59 micrograms/gram dry faeces). CONCLUSIONS The GnRH vaccination protocol failed to induce anoestrus in the treated female elephants. These results indicate that irregular oestrous cycles occur amongst free-ranging elephants and are not restricted to elephants in captivity. The relationship between ecological conditions and endocrine activity were confirmed. Free-ranging female elephants were observed to not cycle continuously throughout the year in the absence of adult bulls.
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Affiliation(s)
- Gabriela Benavides Valades
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, RSA
| | - Andre Ganswindt
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, RSA
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, RSA
| | - Henry Annandale
- Onderstepoort Veterinary Academic Hospital, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, RSA
| | - Martin L Schulman
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, RSA
| | - Henk J Bertschinger
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, RSA
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