SELECTIVE LIVESTOCK GRAZING A TOOL FOR VEGETATION MANAGEMENT

Authors: Ganskopp, David; CRUZ, RUBEN - OREGON STATE UNIVERSITY; Svejcar, Anthony; FARSTVEDT, JERRY - OR DEPT. FISH & WILDLIFE; TAYLOR, FRED - BLM

Submitted to: Oregon Agriculture Experiment Station Special Report
Publication Type: Experiment Station
Publication Acceptance Date: 3/15/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: We report on 4 projects about grazing practices that can enhance or alter forage health or quality. Trials were designed to:1) evaluate the potential for woody plant control by Spanish goats, 2) assess the seasonal impacts of cattle grazing on newly established bitterbrush, 3) define the seasonal preferences of cattle grazing among crested wheatgrass and our native grasses, and 4) see if grazing of Thurber's needlegrass at different times of the growing season can stimulate production of highly nutritious regrowth. Spanish goats showed little potential for control of established Wyoming big sagebrush. When forages were dormant about 8% of their diet came from western juniper, suggesting they have some promise for controlling young juniper. Recently established bitterbrush plants were seldom grazed by cattle when associated grasses were green and leafy. After 3 years, shrubs in early grazed pastures were twice as large as those in pastures with no livestock grazing. Cattle heavily grazed bitterbrush when grasses were dormant and greatly reduced shrub size when compared to plants in non-grazed pastures. Among eight different grasses common to the region cattle favored crested wheatgrass over native grasses early in the growing season and when grasses were flowering. After forages turned brown, the steers' preferences shifted to giant wildrye, but they did make more equitable use of all available grasses. Early to mid-season grazing of Thurber's needlegrass can be used to stimulate high quality regrowth that can be saved for late-season use by growing livestock or wildlife. Production of regrowth is severely limited in dry years, however, and managers should plan on deferring a pasture the next growing if it is heavily grazed in the early to mid-growing season.

Technical Abstract: We report on 4 projects about grazing practices that can enhance or alter forage health or quality. Trials were designed to:1) evaluate the potential for woody plant control by Spanish goats, 2) assess the seasonal impacts of cattle grazing on newly established bitterbrush, 3) define the seasonal preferences of cattle grazing among crested wheatgrass and our native grasses, and 4) see if grazing of Thurber's needlegrass at different times of the growing season can stimulate production of highly nutritious regrowth. Spanish goats showed little potential for control of established Wyoming big sagebrush. When forages were dormant about 8% of their diet came from western juniper, suggesting they have some promise for controlling young juniper. Recently established bitterbrush plants were seldom grazed by cattle when associated grasses were green and leafy. After 3 years, shrubs in early grazed pastures were twice as large as those in pastures with no livestock grazing. Cattle heavily grazed bitterbrush when grasses were dormant and greatly reduced shrub size when compared to plants in non-grazed pastures. Among eight different grasses common to the region cattle favored crested wheatgrass over native grasses early in the growing season and when grasses were flowering. After forages turned brown, the steers' preferences shifted to giant wildrye, but they did make more equitable use of all available grasses. Early to mid-season grazing of Thurber's needlegrass can be used to stimulate high quality regrowth that can be saved for late-season use by growing livestock or wildlife. Production of regrowth is severely limited in dry years, however, and managers should plan on deferring a pasture the next growing if it is heavily grazed in the early to mid-growing season.