Variation in metabolic factors and gonadal, pituitary, thyroid, and adrenal hormones in association with musth in African and Asian elephant bulls

Chave, Emmanuelle; Edwards, Katie L.; Paris, Stephen; Prado, Natalia A.; Morfeld, Kari A.; Brown, Janine L.

doi:10.1016/j.ygcen.2019.02.005

Cited by 21 publications

(20 citation statements)

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“…An adiposity threshold may differ by species. Asian elephants had significantly higher insulin concentrations compared with African elephants, which is in agreement with previous publications (Morfeld and Brown, 2017;Chave et al, 2019). This suggests that Asian elephants may have a lower adiposity threshold, and be more susceptible to developing comorbidities at similar adiposity levels compared with African elephants.…”

Section: Discussionsupporting

confidence: 91%

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Chusyd

Nagy

Golzarri‐Arroyo

et al. 2021

Journal of Experimental Biology

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Many captive Asian elephant populations are not self-sustaining, possibly due in part to obesity-related health and reproductive issues. This study investigated relationships between estimated body composition and metabolic function, inflammatory markers, ovarian activity (females only) and physical activity levels in 44 Asian elephants (n=35 females, n=9 males). Deuterium dilution was used to measure total body water from which fat mass (FM) and fat-free mass (FFM) could be derived to estimate body composition. Serum was analyzed for progestagens and estradiol (females only), deuterium, glucose, insulin and amyloid A. Physical activity was assessed by an accelerometer placed on the elephant's front leg for at least 2 days. Relative fat mass (RFM) – the amount of fat relative to body mass – was calculated to take differences in body size between elephants into consideration. Body fat percentage ranged from 2.01% to 24.59%. Male elephants were heavier (P=0.043), with more FFM (P=0.049), but not FM (P>0.999), than females. For all elephants, estimated RFM (r=0.45, P=0.004) was positively correlated with insulin. Distance walked was negatively correlated with age (r=−0.46, P=0.007). When adjusted for FFM and age (P<0.001), non-cycling females had less fat compared with cycling females, such that for every 100 kg increase in FM, the odds of cycling were 3 times higher (P<0.001). More work is needed to determine what an unhealthy amount of fat is for elephants; however, our results suggest higher adiposity may contribute to metabolic perturbations.

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Section: Discussionsupporting

confidence: 91%

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Chusyd

Nagy

Golzarri‐Arroyo

et al. 2021

Journal of Experimental Biology

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“…In females combined during normal cycling, mean cortisol concentration increased overall with age, and also across age categories with the lowest concentrations in the 0-10-year age category, which then increased in the 11-20 and 21-30 categories, then remained fairly steady PLOS ONE across the 21-60 age categories. Previous studies have shown that serum cortisol also increases with age across Asian elephant bulls [38,39]. The difference in covariance with age across all reproductive states versus limited to normal cycling may in part be due to the exclusion of the acyclic older female, F7NZ, who was the only individual that showed a negative correlation between age and cortisol concentration; and exclusion of pregnancies and lactational anestrus at ages 11-20 years.…”

Section: Demographic Factors and Adrenal Gc Activitymentioning

confidence: 92%

Effects of physiological changes and social life events on adrenal glucocorticoid activity in female zoo-housed Asian elephants (Elephas maximus)

et al. 2020

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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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“…Metabolic status Total cholesterol (mg/dl) [25][26][27][28] Triglycerides (mg/dl) [19,20,[25][26][27][28] Glucose (mg/dl) [ 36% at a FS = 0 44% at a FS = 1 18% at a FS = 2 2% at a FS = 3…”

Section: Body Condition and Metabolic Functionmentioning

confidence: 99%

“…Once known, effective strategies can then be developed to minimize those risks [14]. While mostly applied to disease risks, recent integrative studies conducted by our team utilized a variety of tools and analytical techniques to assess how the captive environment affects physiological and psychological wellbeing of Asian elephants in North America [15][16][17][18][19][20][21][22][23][24][25] and Thailand [26][27][28][29][30]. The North American studies involved~90% of elephants housed in American Zoo and Aquarium (AZA) facilities [31] and was followed a few years later by a series of comparable studies using similar methodologies in Northern Thailand tourist camps.…”

Section: Introductionmentioning

confidence: 99%

Commonalities in Management and Husbandry Factors Important for Health and Welfare of Captive Elephants in North America and Thailand

Brown

Bansiddhi

Khonmee

et al. 2020

Animals

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Simple Summary: There is considerable concern about the welfare of elephants used for education, research, and entertainment purposes in western zoos and Asian tourist camps, and whether captive venues meet the needs of these highly social and intelligent animals. Therefore, it is important to conduct studies to determine how factors in the captive environment affect animal welfare both positively and negatively. The use of multi-disciplinary approaches to assess welfare has aided improvements in the management of captive elephants in North American zoos and Thailand tourist camps. In this paper, we review the most recent findings of our elephant studies that, using similar methodologies, highlight the importance of proper diets, adequate exercise, natural and stimulating environments, and freedom of movement to welfare. Overall, we found a number of commonalities in how environmental factors affect biological function of elephants managed under vastly different conditions. This type of integrative information is important for establishing welfare guidelines to ensure healthy, sustainable global populations of captive elephants.Abstract: This review paper is a synthesis of results from multiple studies that we have conducted over the past several years using similar methodologies to identify factors related to welfare of captive populations of elephants in North American zoos and Thailand tourist camps. Using multiple conservation physiology tools, we found that, despite vastly disparate management systems, there are commonalities in how environmental and husbandry factors affect physical and physiological outcomes. Elephants appear to have better welfare, based on fecal glucocorticoid metabolite (FGM) analyses, when housed under conditions that provide a more enriched, stimulating, and less restrictive environment. We also found it is essential to balance diet and exercise for good body condition and metabolic function. In Thailand, use of tools to control elephants, such as the ankus (i.e., guide, hook) and chains, did not equate to poor welfare per se, nor did riding; however, improper uses were associated with higher wound scores and FGM concentrations. Foot health was good overall in both regions, with cracks being the most common problem, and better foot scores were found in elephants kept on softer substrates. Based on these findings, science-based guidelines are being developed in Thailand, while in North America, changes are being incorporated into elephant standards and husbandry resource guides. Management across venues can be improved by encouraging elephant exploration and exercise, establishing socially compatibility groups, ensuring proper use of tools, and providing balanced diets. We contend there is no "one-size-fits-all" management strategy to Animals 2020, 10, 737 2 of 23 guarantee good welfare for elephants, but there are essential needs that must be met regardless of where or how they are managed. Future studies are needed to find ways to better socialize elephants; determine how temperament...

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Variation in metabolic factors and gonadal, pituitary, thyroid, and adrenal hormones in association with musth in African and Asian elephant bulls

Cited by 21 publications

References 73 publications

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Effects of physiological changes and social life events on adrenal glucocorticoid activity in female zoo-housed Asian elephants (Elephas maximus)

Commonalities in Management and Husbandry Factors Important for Health and Welfare of Captive Elephants in North America and Thailand

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