Foliage acceptability to browsing ruminants in relation to seasonal changes in the leaf chemistry of woody plants in a South African savanna.

Abstract

We investigated seasonal changes in food selection by hand-reared kudus and impalas in savanna vegetation in northern Transvaal, South Africa. The acceptability of the leaves of woody plants to these animals was compared with leaf concentrations of nutrients, fibre components and old leaf phenophases. No consistently significant correlation was found between acceptability and any single chemical factor. Based on an a priori palatability classification, discriminant function analysis separated relatively palatable species from unpalatable species in terms of a linear combination of protein and condensed tannin concentrations. The high acceptability of certain otherwise unpalatable species during the new leaf phenophase was related to elevation of protein levels relative to condensed tannin contents. Species were added to the diet during the dry season approximately in the order of their relative protein-condensed tannin difference.