Advisory Committee Chair
Tim R Nagy
Advisory Committee Members
David B Allison
Steven Austad
Mark Bolding
Janine L Brown
Daniel L Smith, Jr
Document Type
Dissertation
Date of Award
2018
Degree Name by School
Doctor of Philosophy (PhD) School of Health Professions
Abstract
African (Loxodonta africana) and Asian (Elephas maximus) elephant populations are rapidly declining due to poaching, and habitat fragmentation and loss. Due to the precarious situation elephants are facing worldwide, captive elephant populations are being viewed as an insurance policy against extinction. Unfortunately, captive elephant populations are not self-sustaining, in part because of reproductive and health issues. One hypothesis for the observed reproductive and health issues is zoo elephants are obese. The current method of assessing obesity in elephants is based on a qualitative visual tool, the body condition score, which does not quantify fat mass. The purpose of this dissertation was, for the first time, to quantify fat mass in both zoo African and Asian elephants, and characterize the relationship between fat mass and reproductive and metabolic health. Based on deuterium dilution, body fat percentages ranged between approximately 5% and 16%, and 3.5% and 25% in our sample population of African and Asian elephants, respectively. We did not observe a relationship between higher fat mass levels and abnormal reproductive cycling status in either African or Asian elephants; however, we did observe a positive association between fat mass and metabolic biomarkers. In addition, in Asian elephants, older elephants walk less compared to younger elephants, with greater activity levels associated with lower fat mass and serum glucose levels. Finally, based on four different body condition score systems, we found that body condition scoring systems that use a wider range of numerical scores predict absolute fat mass in Asian elephants, while three out of the four systems examined do not predict relative fat mass. Further, it appears that there is an inherent sex bias within the body condition score systems, with males receiving higher scores, speculatively because of their increased fat free mass even though they have less relative fat mass. Although the current method for assessing obesity in an elephant, the BCS, can predict absolute fat mass, it is not sensitive enough to predict relative fat mass, which may be more important for defining obesity. Overall, these data do not support the hypothesis that elephants with greater adiposity are more likely to exhibit abnormal reproductive cycling, but greater relative fat mas may contribute to other metabolic health issues.
Recommended Citation
Chusyd, Daniella, "Adiposity and health in zoo African and Asian elephants" (2018). All ETDs from UAB. 1385.
https://digitalcommons.library.uab.edu/etd-collection/1385