Dietary Overlap between Sheep, Cattle, and Goats When Grazing in Common

Abstract

The chemical and botanical composition of the diets of esophageally fistulated sheep, cattle, and goats was monitored over a period of 1 year at intervals of approximately 2 months. The animals were grazing together in a poplar box (Eucalyptus populnea) woodland community with an understory of shrubs, chiefly Cassia and Eremophila spp., and an herbaceous field layer of grasses and forbs. Diet quality, as assessed by in vitro digestibility, was highest for sheep in all seasons. The degree of dietary overlap, and hence potential competition, was greatest between goats and cattle. Both goats and cattle had a high proportion of browse plants in their diets. Discussion centres on the degree of overlap in the diets and the complementarity of grazing under common-use.