Taurine and zoo felids: considerations of dietary and biological tissue concentrations.

Taurine (TAU) is an essential amino acid required in the diets of Felidae at concentrations ranging between 0.04 and 0.2% on a dry matter (DM) basis (in purified, highly digestible diets, and canned diets, respectively). Although the domestic cat seems to be an appropriate physiologic model for zoo felids, it is sometimes difficult to assess TAU status in zoo feeding programs owing to scattered information on feed ingredient TAU content as well as a lack of normal ranges for assessment of TAU in biological tissues. Knowing that TAU is required in the formulation of hand-rearing diets for exotic felids, the TAU content of 38 ingredients or products used in zoo carnivore feeding or hand-rearing programs was summarized, including 21 new feedstuffs for which TAU data were previously lacking. The kitten milk replacer contained a lower than expected value for TAU. Commercially prepared frozen or canned meat products, seafood products, whole rodent prey, and most strained meat jarred baby foods contained adequate TAU; chunk meats, and some specific types of jarred baby food meats were considerably lower in TAU content (</=0.10% DM) than other foodstuffs. TAU concentrations in plasma and whole blood of eight spp. of zoo felids sampled opportunistically fell within reference ranges for domestic cats (80-120 and 300-600 nmol/ml in plasma and whole blood, respectively). Plasma concentrations are a useful measure of dietary impact, whereas whole blood concentrations seem to reflect tissue storage of this nutrient. Zoo Biol 26:517-531, 2007. (c) 2007 Wiley-Liss, Inc.