Winter Variation in Nutrient and Fiber Content and In vitro Digestibility of Gambel Oak (Quercus gambellii) and Big Sagebrush (Artemisia tridentata) from Diversified Sites in Colorado

Abstract

Nutrient and fiber content and in vitro digestible dry matter (IVDDM) were measured in Gambel oak (Quercus gambellii) and big sagebrush (Artemisia tridentata) samples collected during January from nine geographic areas distributed widely throughout the western half of Colorado, and representing three vegetation types. Coefficients of variation among areas were less than 10% in both species in dry matter content, IVDDM and most cell and cell wall components. Variation appears to be small enough to permit application of a suitably selected, constant value, which would reflect winter nutrient content, fiber content or digestibility of these species, regardless of where collected in Colorado, in surveys where winter nutritional status of big game rangelands is being estimated for management purposes.