Effect of activities on Cortisol and Secretory Immunoglobulin A levels in female captive Asian Elephants (Elephas maximus) in Thailand

Abstract

Asian elephants (Elephas maximus) are the idolized species in Thailand that have been working in tourist-entertaining camps for over decade. Thai elephant camps have provided various tourist activities which directly impact on animal well-being. Recently, secretory immunoglobulin A (sIgA) is proved to be a potential welfare biomarker in Asian elephants which can contribute additional data in both positive and negative stimuli. We investigated sIgA responses and glucocorticoid hormones (GC) by assuming that high sIgA and low GCs, and low GC to sIgA ratio indicate the positive welfare. Forty-four domesticated female elephants from six elephant camps were divided into three groups; saddle-, bareback-, and no-riding. For one year, salivary and fecal samples were monthly collected for sIgA and glucocorticoid hormone (GC) measures with body condition, foot health, and skin wound score evaluation. Generalized Least Square was used to statistical analysis and the results were diverse in different management. Overall, there were no differences in salivary sIgA between the three activities (p>0.05). The bareback-riding activity presented lower salivary cortisol and higher fecal sIgA in overall measurements compared to other activities (p<0.01), while the saddle type had the lowest fecal glucocorticoid metabolite (FGM) concentrations (p<0.01). SIgA and GC results were not consistent and high variability in both two sample matrices was found creates difficulty in interpretation. However, the results suggested that there were more factors related to elephant welfare besides elephants participating in riding activities or not.