Plasma vitamin E and other analyte levels in Nepalese camp elephants (Elephas maximus)

Plasma concentrations of alpha-tocopherol (vitamin E) and other analytes in Asian elephants (Elephas maximus) in Nepal were determined during typical work camp management of the elephants. Elephants foraged for food for 4-6 hr each day under the control of mahouts and were also provided daily with cut forage and supplements of unhusked rice, cane molasses, and salt. Blood samples were taken monthly for 1 yr without chemical restraint from 26 female elephants in four camps. Elephants were 6-60+ yr of age. Mean (+/-SEM) alpha-tocopherol concentration was 0.77+/-0.047 microg/ml, with a range of 0.23-1.57 microg/ml. Subadults had lower concentrations than did older elephants, and there were significant differences in mean concentrations from different camps and in mean monthly concentrations. Plasma alpha-tocopherol concentration appears to vary widely between individuals, and a single value of <0.3 microg/ml is not sufficient to diagnose incipient vitamin E deficiency. Mean (+/-SEM) plasma retinol (vitamin A) concentration was 0.063+/-0.003 microg/ml with a range of 0.01-0.12 microg/ml. Subadults had higher concentrations than did older elephants, and mean retinal values differed significantly among camps. Beta-carotene was not found in plasma. Twenty-five other analytes determined or derived were generally similar to those reported in other Asian and African (Loxodonta africana) elephants. Estimates of nutrient intake, based upon diet composition, suggested that dietary concentrations of zinc and sodium may have been marginal, but the absence of signs of any nutrient deficiencies indicates that dietary husbandry in these elephant camps was generally satisfactory.