A comparative haematological analysis of Asian Elephants Elephas maximus Linnaeus, 1758 (Mammalia: Proboscidea: Elephantidae) managed under different captive conditions in Sri Lanka

Abstract

Haematological parameters were assessed from elephants of three institutions in Sri Lanka with different captive conditions, in order to evaluate if different captive conditions influence the physiology of the animals. The institutions were: The National Zoological Gardens (NZG), where elephants live a comparatively sedentary lifestyle, Pinnawala Elephant Orphanage (PEO), where elephants are allowed to walk and engage in intra-specific behaviours, and Millennium Elephant Foundation (MEF), where the elephants are used for tourist rides. Four adult females were examined from the NZG, while only two males and two females could be examined from PEO and MEF respectively. All animals were sampled on four consecutive days. Blood glucose levels, total white blood cells (WBC), red blood cells (RBC), packed cell volume (PCV), mean corpuscular volume (MCV) and differential white blood cell counts were carried out. Certain blood parameters of the elephants from NZG differed significantly from the parameters of the elephants from PEO and MEF. These were, the total WBC counts (Kruskal-Wallis, H=21.92, 2d.f., P=0.000), the lymphocyte count (Kruskal-Wallis, H=16.40, 2d.f., P=0.00) and the Neutrophil: Lymphocyte ratios (Kruskal-Wallis , H=14.58, 2d.f., P less than 0.05). PCV , blood glucose levels and monocyte counts were also shown to be significantly different among the three groups (Kruskal-Wallis P less than 0.000). We suggest that differences in the stress levels associated with the different management methods might influence these haematological values.