Influence of season, tourist activities and camp management on body condition, testicular and adrenal steroids, lipid profiles, and metabolic status in captive bull elephants in Thailand

Abstract

We previously found relationships between body condition and physiological function affecting health and welfare of female tourist camp elephants in Thailand, and used that approach to conduct a similar study of bulls elephants in the same camps (n = 13). Elephants received a body condition score (BCS) every other month, and fecal glucocorticoid metabolite (FGM) concentrations were measured in twice monthly samples for 1 year. Effects of season, camp management and tourist activity on lipid profiles [total cholesterol (TC), low density lipoproteins (LDL), high density lipoproteins (HDL), triglycerides (TG)] and metabolic factors [insulin, glucose, fructosamine, glucose to insulin ratio (G:I)] were determined and correlated to measures of body condition, testosterone and adrenal function. Positive correlations were found between BCS and TG, between FGM and TG, HDL and glucose, and between testosterone and HDL (p<0.05), whereas BCS and testosterone were both negatively associated with the G:I (p<0.05). Elevated FGM concentrations were associated with altered lipid profiles and metabolic status and were higher in winter compared to summer and rainy seasons. Insulin and glucose levels were higher, while the G:I was lowest, in the winter season. Strong positive associations (p<0.001) were found between TC and HDL, LDL and HDL and glucose, and glucose and insulin. By contrast, negative relationships (p<0.001) were found between the G:I and HDL and glucose, and between insulin and G:I. Differences also were found between High and Low tourist season months for FGM, insulin, and G:I, which may be related to tourist activities. Last, there was notable variation among the camps in measured parameters, which together with the tourist season effect suggests camp management related to tourism may affect physiological function and welfare; some negatively like feeding high calorie treats, but others are positively, like exercise. Last, compared to females, bulls elephants appear to be in better physical health.