Nutritional quality of forages used by elk in northern Idaho

Abstract

The nutritional quality (digestible energy, crude protein, and minerals) of 7 known elk (Cervus elaphus Linnaeus) forages was assessed at 4 different time periods from May to November. Species evaluated were elk sedge (Carex geyeri Boott), Kentucky bluegrass (Poa pratensis Linnaeus), western goldthread (Coptis occidentalis Nuttall), clover (Trifolium repens Linnaeus), service-berry (Amelanchier alnifolia Nuttall), redstem ceanothus (Ceanothus sanguineus Pursh), and Scouler willow (Salix scouleriana Barratt). Mineral concentrations generally met estimated requirements for elk in all seasons, except sodium remained below requirements in all seasons. Crude protein in most plant species sampled was adequate for adult gravid or lactating cows throughout the year, although concentrations in graminoids fell below requirements during August. Forage provided adequate digestible energy for gravid or lactating cows only during May, indicating potential deficiencies in summer and autumn. Elk must be selective of plant parts, plant taxa, and foraging habitat to gain adequate nutrition. In this area, summer and fall forage quality may be critical to lactating cow elk.