Circulating nutrients and hematological parameters in managed African elephants (Loxodonta Africana) over a 1-year period.

African elephants (Loxodonta Africana) are currently considered a vulnerable species. One key to improving methods of species management is to better monitor and understand elephant nutrition. Analyzing circulating nutrients is one of the best and least invasive methods of monitoring managed elephant nutrition, but limited reference values are available. This study examined the circulating basic hematology concentrations, minerals, vitamins A, D, and E, and fatty acids of six African elephants (two males and four females) at the North Carolina Zoo collected monthly from March 2016 to April 2017 and compared levels among seasons. Creatinine (CRE) and albumin had seasonal differences (p ≤ .05). Calcium, magnesium, phosphorus, potassium, selenium, zinc, cobalt, manganese, and molybdenum displayed seasonal differences (p ≤ .05). Retinol and 25-hydroxyvitamin D2 had seasonal differences (p ≤ .05). Linoleic acid, α-linolenic acid, arachidonic acid, total omega-3 fatty acids, total omega-6 fatty acids, and the omega-6 to omega-3 ratio showed seasonal differences (p ≤ .05). Findings suggest that exogenous vitamin E supplements may not be necessary with a mixed feedstuff diet (hay, fortified concentrate pellet, browse, and produce) based on circulating values. This data offer updated information on circulating reference values and novel circulating concentrations of nutrients for Southeastern US managed African elephants that can be used to inform nutritional and health management in all similar habitats.