Browsing Journal of Range Management, Volume 50, Number 6 (November 1997) by Title
Now showing items 11-14 of 14
Preference and behavior of cattle grazing 8 varieties of grassesWe compared the forage preferences of steers grazing among 8 varieties of grasses at 2 stages of phenology on the Northern Great Basin Experimental Range near Burns, Ore. Varieties included: 'Nordan' (Agropyron desertorum (Fischer ex Link)Schultes) and 'CD-II' (A. desertorum X A. cristatum (L.) Gaertner) crested wheatgrass; 'Magnar' and 'Trailhead' Basin wildryes (Leymus cinereus (Scribner &Merrill) A. Love); 'Goldar' bluebunch wheatgrass (Pseudoroegneria spicata (Pursh)A. Love); 'Bozoisky-Select' Russian wildrye (Psathyrostachys junceus (Fischer) Nevski); 'Bannock' thickspike wheatgrass (Elymus lanceotatus ssp. lanceolatus (Scribner &J.G. Smith) Gould), and 'Secar' Snake River wheatgrass (proposed nomenclature Elymus lanceolatus ssp. wawawaiensis (Scribner &J.G. Smith) Gould). Three esophageal-fistulated steers grazed each paddock, with 3 paddocks grazed at the boot stage of development, and 3 paddocks grazed after grasses entered quiescence. In boot-stage trials, steers were very selective and collectively harvested 53% of total bites from the preferred CD-II and Nordan. These crested wheatgrasses also ranked higher (P < 0.05) in bites visit and time/visit. Magnar, Trailhead, and Bozoisky-Select were avoided. When grasses were quiescent, steers were less selective; and CD-II, Nordan, Goldar, Bannock, and Bozoisky-Select were all equally acceptable. Magnar and Trailhead were again avoided. Steers consistently took more bites (p < 0.05) from preferred forages and regrazed preferred plants before any variety was depleted. Mean distance traveled between successive feeding stations was greater during bootstage trials (2.4 m) than at quiescence (1.4 m), suggesting steers searched among the nearest 48 neighboring plants in boot-stage trials and the nearest 24 neighbors during quiescence. Measures of grazing time per variety were strongly correlated (r > 0.95, P < 0.01) with total bites harvested from varieties and are probably adequate for ranking relative preferences of steers. By selectively grazing at both stages of phenology, cattle diets were higher in CP, P, and ADL than the standing crop. During boot-stage trials, diets were also higher in Ca and Mg than forage analyses would suggest. Except for phosphorus, the nutritive content of all varieties was satisfactory for lactating beef cattle at both stages of phenology. Given their proven ease of establishment, competitive ability, nutritional value, grazing tolerance, and high relative palatability, we suggest the crested wheatgrasses (CD-II and Nordan), are excellent candidates for reclaiming or establishment of pastures for beef production programs in the northern Great Basin.
Seeded versus containerized big sagebrush plants for seed-increase gardensSeed production of big sagebrush (Artemisia tridentata Nutt.) plants established from containerized seedlings was compared to plants established by direct seeding. A garden of 'Hobble Creek' mountain big sagebrush (Artemisia tridentata ssp. vaseyana (Rydb.) Beetle) and a garden of Gordon Creek Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle &Young) were established in central Utah for this study. Each garden consisted of 10 rows of plants. Seed-derived plants were established on odd-numbered rows and container-derived plants in even-numbered rows. Seed-derived plants produce more seeds, larger top growth, deeper roots, lateral roots nearer the soil surface, and heavier root systems than container-derived plants. Seed-derived plants also produced large prominent tap roots; the containerized plants did not. Seed-derived plants had a zero death rate for the 4 study years. Death rates for containerized plants were 16% ('Hobble Creek') and 13% (Gordon Creek). To help meet seed demands, growers should establish seed-increase gardens with seed-derived plants. A cautionary note: It is unknown if the use of container-derived plants for adaptation trials might erroneously influence the results of such studies. However, the root development problems described in this study should cast some doubt.
Vegetation, cattle, and economic responses to grazing strategies and pressuresRotation grazing strategies have been proposed to increase stocking capacity, improve animal gains, and improve forage production and range condition. We compared continuous or season-long, 4-pasture rotationally deferred, and 8-paddock time-controlled rotation grazing on mixed-grass rangeland near Cheyenne, Wyo. from 1982 through 1994. Stocking rates under light, moderate and heavy grazing averaged 21.6, 47.0, and 62.7 steer-day ha-1; grazing pressures were 11.0 to 90.1 steer-day Mg-1 of forage dry matter produced. We estimated above and below-ground biomass, botanical composition and basal cover. Bare ground and cover of warm-season grasses, forbs, and lichens were greater under heavy stocking; cover of litter, western wheatgrass, and total cool-season graminoids were greater under light stocking. Stocking rate and grazing strategy had no effect on above-ground biomass and little effect on below-ground biomass. Under heavy stocking, percent of above-ground biomass contributed by forbs increased, especially under time-controlled rotation grazing, and that of western wheatgrass decreased. Otherwise, effects of grazing strategy, level vs. slope, and north vs. south slope on vegetation were insignificant. Steer average daily gain decreased linearly as grazing pressure increased (r2 = 0.44); grazing strategies had no significant effect. When cattle prices are favorable, the stocking rates that are most profitable in the short run may be high enough to reduce range condition.
Wildlife numbers on late and mid seral Chihuahuan Desert rangelandsSeasonal wildlife observations were made along transects on 2 pastures in late seral and 2 pastures in mid seral condition in southcentral New Mexico in non-drought and drought years (1993, 1994). Remaining climax vegetation was about 64% and 57% on late seral pastures. About 37% and 32% of the climax vegetation remained on mid seral pastures. Total wildlife and total bird sightings/km2 during the study period were higher (P < 0.10) on the mid compared to late seral rangelands. The same number of wildlife species were seen on the late and mid seral pastures. Sightings of scaled quail (Callipepla squamata Vigors), mourning doves (Zenaida macroura Linnaeus), prong-horn (Antilocapra americana Ord), and desert cottontails (Sylvilagus auduboni Mearns) showed no differences (P> 0.10) between late and mid seral condition rangelands. Black-tailed jackrabbit (Lepus californicus J.A. Allen) numbers were higher (P