Livestock grazing effects on forage quality of elk winter range

Carefully-managed livestock grazing has been offered as a tool to improve t he forage quality of graminoids on big game winter range. Formal testing of this theory has thus far been done using hand clippers rather than livesto ck grazing. We report winter standing reproductive culm, crude protein, in vitro dry matter digestibility, and standing crop responses of bluebunch wh eatgrass (Agropyron spicatum [Pursh] Scribn, & Smith), Idaho fescue (Festuc a idahoensis Elmer), and elk sedge (Carex geyeri Boott) to late-spring dome stic sheep grazing, The study was conducted in 1993 and 1994 on a big game winter range in the Blue Mountains of northeastern Oregon, Sheep grazing an d exclusion treatments were applied to 20-ha plots at 3 sites on the study area. Targeted utilization for grazed plots was 50% graminoid standing crop removal during the boot stage of bluebunch wheatgrass, Grazing did not inf luence the number of standing reproductive culms per plant in bluebunch whe atgrass. Crude protein and in vitro dry matter digestibility of bluebunch w heatgrass in grazed plots increased by 1.0 and 4.3 percentage points, respe ctively, over ungrazed plots, Grazing reduced the standing crop of bluebunc h wheatgrass by 116.9 kg ha(-1) DM, Standing Idaho fescue reproductive culm s decreased by 0.7 culms plant(-1) under grazing. Crude protein of Idaho fe scue in grazed plots was 1.3 percentage points greater than in ungrazed plo ts. Crude protein and in vitro dry matter digestibility responses of elk se dge were inconsistent between years and may be related to utilization or gr owth differences between years. The Levels of forage quality improvement in bluebunch wheatgrass and Idaho fescue obtained in this study could benefit the nutritional status of wintering Rocky Mountain elk (Cervus elaphus nel soni Bailey). More research is needed regarding the effects of grazing on t he winter forage quality of elk sedge.