Cattle Diets in the Blue Mountains of Oregon II. Forests

Esophageally fistulated cows were used on forested range in northeastern Oregon to collect diet samples which were then analyzed by the microhistological technique. Grasses, forbs, and shrubs averaged 61, 16, and 23% of the diet, respectively. Composition of diets differed among years and with seasonal advance. Idaho fescue and elk sedge were the most important forage species consumed. Forbs were used heavily in the early part of the grazing season before maturation. Browse comprised as much as 47% of the diet when green grass was unavailable. Cattle were opportunistic grazers and did not limit their selection to grass species. On forested ranges cattle diets varied among grazing periods within each year as well as among years.