Measuring Consumption and Digestibility of Winter Range Plants by Sheep

Abstract

EXTENSIVE areas of desert range in the intermountain area are the sole ;source of forage for sheep during the winter grazing season. The diversity in soil, climate, and topography provides a variety of native forage for grazing animals, and the nutritive content of the diet varies widely depending upon environmental conditions, and animal selectivity for various species and parts of plants. Thus, a knowledge of the nutritive qualities of native forage plants is of extreme importance for a better understand-ing and appraisal of the animal's diet under range conditions. Most studies of the nutrients supplied by range forage have dealt with chemical analyses of bulk samples of herbage collected from the range. However, chemical content is not a reliable index to availability of the various nutrients and is of limited value unless accompanied by digestibility determinations or balance trials. For this reason a method for determining digestibility of native forage under range conditions was developed and used in obtaining the data presented in this paper.