The role of secondary compounds in foraging on Mediterranean rangelands

Abstract

Goats are primary consumers of the Mediterranean shrubby vegetation, and thereby shape the diversity, structure and dynamics of these extensive ecosystems. Low nutritional quality and high levels of secondary compounds can result in low consumption of Mediterranean shrubs by herbivory. Goats were allowed to choose between Mediterranean shrubs containing tannins and other Mediterranean shrubs containing tannins and saponins. Twelve goats offered tannin-containing shrubs consumed less biomass than animals offered shrubs containing tannins and saponin. Simultaneous consumption of shrubs that contain tannins and saponin may promote chemical interactions that inhibit toxin absorption from the intestinal tract. Besides complementary tannin and saponin interactions, biodiversity of Mediterranean shrubs also plays a positive role in increased biomass intake by goats.