Unravelling the conundrum of tannins in animal nutrition and health

Abstract This paper examines the nutritional and veterinary effects of tannins on ruminants and makes some comparisons with non‐ruminants. Tannin chemistry per se is not covered and readers are referred to several excellent reviews instead: (a) Okuda T et al. Heterocycles 30:1195–1218 (1990); (b) Ferreira D and Slade D. Nat Prod Rep 19:517–541 (2002); (c) Yoshida T et al. In Studies in Natural Product Chemistry . Elsevier Science, Amsterdam, pp. 395–453 (2000); (d) Khanbabaee K and van Ree T. Nat Prod Rep 18:641–649 (2001); (e) Okuda et al. Phytochemistry 55:513–529 (2000). The effects of tannins on rumen micro‐organisms are also not reviewed, as these have been addressed by others: (a) McSweeney CS et al.…