Use of Range Shrubs to Meet Nutrient Requirements of Sheep Grazing on Crested Wheatgrass during Fall and Early Winter

Abstract

This study considered the feasibility of supplementing crested wheatgrass (Agropyron cristatum Fisch.) forage with some common rangeland shrubs. The necessary proportions of shrub and grass in the diet to meet protein and energy requirements were calculated for gestating sheep during the late fall and early winter grazing season. Shrubs studied included fourwing saltbush Atriplex canescens Pursh. Nutt.), winterfat (Ceratoides lanata (Pursh Howell), rubber rabbitbrush (Chrysothamnus nauseosus ssp. albicaulis, (Nutt) Rydb.), and big sagebrush (Artemisia tridentata ssp. vaseyana Nutt.). The shrubs were consistently higher in both total and digestible protein than crested wheatgrass over the period of study. Fourwing saltbush and winterfat with 8.24 and 6.31% digestible protein, respectively, were found to be the most promising shrubs to be used to supplement the low protein content of crested wheatgrass for late fall grazing. To meet dietary requirements for gestating sheep would require a minimum of 56 to 69% of fourwing saltbush and winterfat respectively, in the diet. Sagebrush and rabbitbrush were lower in digestible protein content, 4.04 and 4.43%, respectively, and therefore could not be used alone with crested wheatgrass.