A Survey of Serum and Dietary Carotenoids in Captive Wild Animals

Abstract

Accumulation of carotenoids varies greatly among animal species and is not fully characterized. Circulating carotenoid concentration data in captive wild animals are limited and may be useful for their management. Serum carotenoid concentrations and dietary intakes were surveyed and the extent of accumulation categorized for 76 species of captive wild animals at Brookfield Zoo. Blood samples were obtained opportunistically from 275 individual animals immobilized for a variety of reasons; serum was analyzed for alpha- and beta-carotene, lutein + zeaxanthin, lycopene, beta-cryptoxanthin and canthaxanthin. Total carotenoid content of diets was calculated from tables and chemical analyses of commonly consumed dietary components. Diets were categorized as low, moderate or high in carotenoid content as were total serum carotenoid concentrations. Animals were classified as unknown, high, moderate or low (non-) accumulators of dietary cartenoids. Nonaccumulators had total serum carotenoid concentrations of 0-101 nmol/L, whereas accumulators had concentrations that ranged widely, from 225 to 35,351 nmol/L. Primates were uniquely distinguished by the widest range of type and concentration of carotenoids in their sera. Most were classified as high to moderate accumulators. Felids had high accumulation of beta-carotene regardless of dietary intake, whereas a wide range of exotic birds accumulated only the xanthophylls, lutein + zeaxanthin, canthaxanthin or cryptoxanthin. The exotic ungulates, with the exception of the bovids, had negligible or nondetectable carotenoid serum concentrations despite moderate intakes. Bovids accumulated only beta-carotene despite moderately high lutein + zeaxanthin intakes. Wild captive species demonstrated a wide variety of carotenoid accumulation patterns, which could be exploited to answer remaining questions concerning carotenoid metabolism and function.

Fat Soluble Vitamins in Blood and Tissues of Free-Ranging and Captive Rhinoceros

“…In this respect, rhinoceroses resemble elephants that also display remarkably low circulating levels of these vitamins compared to perissodactyls (Dierenfeld and Traber, 1992;Dierenfeld et al, 1998). Additionally, similar to the findings of Slifka et al (1999), we did not detect circulating carotenoids in free-ranging and captive black rhinoceroses. In contrast, levels of 0.60 Ϯ 0.24 g/ml were detected in semi-free-ranging Przewalski horses (Equus caballus), which were approximately five times those reported in stabled domestic horses used as a comparative model (Dierenfeld et al, 1997).…”

“…Slifka et al (1999) did not detect circulating carotenoids in three captive black rhinoceroses. In this study, we investigated the vitamin A and E content of blood and tissues of captive and freeranging rhinoceroses.…”

Bioavailability of Dietary Carotenoids: Intestinal Absorption and Metabolism

“…These results suggest that humans accumulate carotenoids selectively, possibly by discriminative uptake and/or re-excretion by intestinal cells and metabolism in the body, in contrast with mice. Human beings and other primates are also unique species in that they accumulate carotenoids at a high level (Slifka et al 1999). The selective accumulation acquired by humans during evolution can be neither fortuitous nor meaningless, but must be relevant to human health.…”

Mammalian carotenoid absorption and metabolism

“…Primates, similarly to humans, accumulate a wide range of carotenoids in high concentrations, while other mammalian species accumulate only one speci®c carotenoid/class of carotenoid or no carotenoids at all. Birds preferentially accumulate xanthophylls in most tissues [64]. Contrary to past studies, Chew et al [66] recently reported that the domestic cat absorbs signi®cant amounts of b-carotene from dietary sources.…”

“…Carotenoids are ubiquitous in mammalian tissues and the accumulation of carotenoids among animals is species speci®c and highly variable [64]. These differences could be explained by dietary intake and/or species differences in absorption and metabolism, such as gut motility or handling of lipoproteins by the body.…”