GRAZING EFFECTS ON NUTRITIONAL QUALITY OF BLUEBUNCH WHEATGRASS FOR ELK

We tested the hypothesis that nutrient content of bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. & Smith) either cattle grazed in the spring, rested from cattle grazing for a full year, or given long term rest would all be equal during the given season at 1 location, A 3 pasture rest-rotation grazing system and an exclosure on the Mt. Fle ecer elk winter range in southwestern Montana were studied during 4 se asons over 3 years, Only nitrogen (N) and phosphorus contents were gen erally greater in the spring grazed regrowth pasture, However, regrowt h from bluebunch wheatgrass grazed in the spring did not improve the s pecies nutrient content for wildlife the following winter over nongraz ed treatments. During winter when elk (Cervus elaphus nel-soni Bailey) are present, N, TDN, and IVDMD were not different among the 3 treatme nts, Elk were determined unlikely to consume enough bluebunch wheatgra ss to meet protein maintenance requirements during winter, Our finding s resulted from analyses repeated over the 3 years for a complete cycl e of a 3 pasture rest-rotation system: however, our hypothesis needs t o be tested at other locations before assuming the same results elsewh ere.