Diets of Steers on a Shrub-Steppe Rangeland in South-Central Washington

Abstract

Botanical composition of steers' diets on a shrub-steppe rangeland in south-central Washington was examined by inspection of finely ground fecal samples viewed through a microscope. Four species, Cusick bluegrass, Thurber needlegrass, hawksbeard and bluebunch wheatgrass, comprised 92% of the total diet. Grasses accounted for 73% of the diet and forbs and half shrubs contributed 26%. Botanical composition of the diets changed throughout the spring grazing season with changing availability and maturation of herbage. Preference indices in decreasing order were: Cusick bluegrass > Thurber needlegrass > hawksbeard > bluebunch wheatgrass, but bluebunch wheatgrass was the most abundant species in the pasture. The second most abundant grass, Sandberg bluegrass, was not selected by steers.