Effects of diet composition on risk of abnormal blood values in bottlenose dolphins (Tursiops truncatus), beluga whales (Delphinapterus leucas), and killer whales (Orcinus orca)

Citation

Bissell H and Nollens H. 2021. Effects of diet composition on risk of abnormal blood values in bottlenose dolphins (Tursiops truncatus), beluga whales (Delphinapterus leucas), and killer whales (Orcinus orca). In Brooks M, Koutsos E, and Henry B Eds. Proceedings of the Fourteenth Conference on Zoo and Wildlife Nutrition, Zoo and Wildlife Nutrition Foundation and AZA Nutrition Advisory Group, Virtual.

Abstract

The lack of data about piscivorous marine mammals’ nutrient requirements or how well different types of fish meet those needs has implications for both the health and welfare of zoo animals as well as for assessing the health and sustainability of wild populations. This study utilized long-term (6-13 years) data about the individual diets and blood values of 158 Atlantic bottlenose dolphins, 33 killer whales, and 28 beluga whales housed at SeaWorld parks to understand how diet impacts animal health. Data were extracted from our medical records system and limited to animals with at least 365 days of feeding data and at least 10 blood samples. Each blood parameter was compared with published reference ranges for each species, and values outside the 95% CI were flagged. Clusters of flags were used to classify the blood sample as being indicative of 15 “syndromes”, such as renal insufficiency, hepatic insufficiency, or anemia. Diets were calculated based on recorded fish intake each day using yearly average nutrient composition of each fish type including macronutrients and minerals. In the first analysis, we calculated the odds ratios of having any lifetime blood sample test positive for a syndrome based on a lifetime average diet, while in the second, we calculated the odds ratios of any specific blood sample testing positive for a syndrome based on the previous 90 days of diet, adjusting for age and sex.

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