William C. Krueger

Cattle Grazing and Behavior on a Forested Range

Environmental and topographic parameters on a mountainous forested range were analyzed to establish causes of cattle behavioral responses. Distinct home range groups of cattle were identified through examination of quality and patterns of forage use, cattle distribution, herd social structure, and cattle activities. The home range of one group encompassed only upland areas. Water and vegetation type were important parameters in determining area and degree of use. Vertical distance above water was the most important factor in determining vegetation utilization on moderately steep slopes. Time after sunrise and relative humidity factors were key factors in determining kind and timing of cattle activity. Cattle have been grazing forested ranges in western United States for more than 125 years (United States Senate 1936). Grazing units on the forests have been fenced, restricting livestock to given areas. Fencing placed definite limits on forage and often increased animal concentration on key vegetation types. Some vegetation types were over-utilized while others were left ungrazed. As the demand for more and varied uses of mountain land areas increases, it becomes important to enhance livestock distribution, alleviating concentration problems and minimizing real or potential conflicts with other resource uses. Detailed information assessing the pattern of livestock use, the types and amounts of forage consumed, and livestock distribution is required. This is only baseline information; in order to apply it, one must know the cause and the mechanism of each parameter. Determining causes for observed actions of cattle overlaps range management and applied behavioral sciences. External physical and biotic influences interact with the animal’s innate behavioral complex to produce a given response. Measurement of influencing parameters must be matched with the animal response and examined to establish the cause and effect relationship. Distance from water, topography, temperature, humidity, and forage availability have been rated as important parameters in modifying animal behavior. Herd structure is a behavioral factor which could have considerable influence on grazing patterns and forage use. Many researchers have observed a given event and assessed the impact on vegetation, but those observations were often not analyzed in terms of what caused the event. This research was designed to quantitatively define the influences of topography, environment and biotic factors on cattle distribution and grazing habits. Cattle behavioral responses to external factors were described by regression relationships.

Competition for Resources Between Understory Vegetation and Overstory Pinus Ponderosa in Northeastern Oregon

The objective of this research was to determine which environmental resources, light, water, and/or nutrients, control understory plant production in a Pinus ponderosa forest in northeastern Oregon. A split-plot experimental design, with three 5.0-ha blocks, four treatments, and 44 plots, was established in the summer of 1985. Twenty plots (4 X 4 m) were trenched (root-reduction treatment) °1 m in depth, and 24 non-trenched plots (root-control treatment) were used to assess the effects of root competition of overstory trees on understory plants. Trees were commercially thinned (canopy-reduction treatment) in half of each block (2.5 ha) during the winter and early spring of 1986, from a density of 345 to 148 trees/ha to increase light levels to the understory. Thinning significantly increased photosynthetically active radiation, decreased midday relative humidity, and increased midday air temperatures. Xylem potential of the dominant graminoid (Carex geyeri), soil water potential, mineralizable nitrogen, and pH were increased within the root-reduction vs. the root-control treatments. Micro- and macronutrients in C. geyeri and Symphoricarpos albus, the dominant shrub, were influenced in both treatments. Increasing light did not increase understory biomass production. Reducing root competition for soil water and nutrients increased understory aboveground biomass by 53 and 94% in 1986 and 1987, respectively. This research demonstrated that belowground resources were the primary controlling factors of understory production in P. ponderosa forests in northeastern Oregon.

Impacts of cattle on streambanks in northeastern Oregon.

Impacts of a Iate season livestock grazhq strategy on streambank erosion, morphology, and undercutting were studied for 2 years along Catherine Creek in northeastern Oregon. Streambank loss, disturbance, and undercutting were compared between grazing treatments, vegetation type, and stream-meander position. No significant differences were found among vegetation types or stream-meander location. Significantly greater streambank erosion and disturbance occurred in graxed areas than in exclosed areas during the 1978 and 1979 graxhrg periods. Over-winter erosion was not significantly different among treatments. However, erosion reIated to livestock grazing and trampling was enough to create significantly greater annual streambank losses when comp8red to ungraxed areas. Vegetation is an important component of the riparian/stream ecosystem (Campbell and Franklin 1979, Jahn 1978). The effects from livestock grazing in these ecosystems have been shown to vary greatly depending upon the nature of the stream studied. Behnke and Zarn (1976), Dehlem (1979), Duff (1979), Gunderson (1968), and Heede (1977) found livestock grazing and excessive trampling caused a decrease in bank undercuts, increases in channel widths, and a general degradation of fish habitat. Buckhouse et al. (1981), Hayes (1978), and Knight (1978) found that stream channel movement did not occur more frequently in grazed riparian ecosystems than in ungrazed riparian ecosystems. In 1978 a study was initiated to examine effects of late season cattle grazing in riparian ecosystems that are separated from upland communities. The objectives of this study were to compare streambank morphology, erosion, and undercutting between areas of streambanks that were grazed under a late season grazing strategy and areas of streambanks that were totally excluded from livestock grazing.

Cattle grazing influence on a mountain riparian zone.

A combination of management and physical topographic constraints caused cattle to concentrate on the riparian zone early in the grazing season in 1977 and 1978. A large percentage of cattle days and vegetation utilization on the riparfan zone occurred in the first 4 weeks of the grazing period. Utilization on herbaceous vegetation was 76 and 72% in 1977 and 1978, respectively. Impact of grazing on the most prevalent species, Kentucky bluegrass was minimal. Shrub use increased with increased maturity of herbaceous vegetation. Utilization of major shrubs was not excessive in either year, and very likely had no long-term effects on either the abundance or vigor of the shrubs. Riparian zones are those areas associated with streams, lakes, and wet areas where plant communities are predominately influenced by their association with water. They are key areas for a wide variety of uses. Fisheries and wildlife biologists have suggested mountain riparian zones are critical habitats in maintaining viable populations of fish, birds, small and big game animals (Ames 1977, Hubbard 1977). These areas are extremely important in providing forage and water for domestic animals (Phillips 1965, Cook 1966). Watershed specialists have indicated that the riparian zone plays an integral role in water quantity and quality (Horton and Campbell 1977). The U.S. government land management agencies, committed by law to manage for multiple use, have identified riparian zones as critical management areas.

Effects of established perennial grasses on yields of associated annual weeds.

Perennial grasses are needed for seeding annual grasslands in the Mediterranean/maritime climatic regime of southwest Oregon. Selection of plants for reseeding purposes would be facilitated by identification of perennial grasses that, once established, are able to suppress resident annual plant production. Perennial grasses were transplanted and allowed to establish in the absence of competition for the first growing season at 2 sites in the foothills of southwest Oregon. After the first growing season, resident annual plants were allowed to reinvade. Perennial grasses such as Berber orchardgrass (Dactylis glomerata L. var. Berber) and Idaho fescue (Festuca idahoensis Elmer) that begin growth early suppressed annuals more effectively than later growing perennial grasses such as intermediate and tall wheatgrasses (Agropyron intermedium (Host.) Beauv. and A. elongatum (Host.) Beauv., respectively). Of the perennial grasses adapted to these sites, those which initiated growth earliest, maintained some growth through winter months, and matured earliest were the best competitors.

Livestock grazing effects on forage quality of elk winter range

Carefully-managed livestock grazing has been offered as a tool to improve the forage quality of graminoids on big game winter range. Formal testing of this theory has thus far been done using hand clippers rather than livestock grazing. We report winter standing reproductive culm, crude protein, in vitro dry matter digestibility, and standing crop responses of bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. &Smith), Idaho fescue (Festuca idahoensis Elmer), and elk sedge (Carex geyeri Boott) to late-spring domestic 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 and 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 influence the number of standing reproductive culms per plant in bluebunch wheatgrass. Crude protein and in vitro dry matter digestibility of bluebunch wheatgrass in grazed plots increased by 1.0 and 4.3 percentage points, respectively over ungrazed plots. Grazing reduced the standing crop of bluebunch wheatgrass by 116.9 kg ha-1 DM. Standing Idaho fescue reproductive culms decreased by 0.7 culms plant-1 under grazing. Crude protein of Idaho fescue in grazed plots was 1.3 percentage points greater than in unglazed plots. Crude protein and in vitro dry matter digestibility responses of elk sedge were inconsistent between years and may be related to utilization or growth 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 nelsoni Bailey). More research is needed regarding the effects of grazing on the winter forage quality of elk sedge. DOI:10.2458/azu_jrm_v53i1_clark

Viewpoint: livestock influences on riparian zones and fish habitat: literature classification.

A key was used to classify articles about livestock influences on riparian zones and fish habitat into 3 classes: papers that contained original data, those that were commentary, and reports about methodology such as classification systems, policies, and monitoring criteria. Four hundred and twenty-eight of the total articles were directly related to grazing impacts on riparian zones and fish habitat. Only 89 of these grazing impact articles were classified as experimental, where treatments were replicated and results were statistically valid. This analysis revealed several limitations of riparian grazing studies that included: (1) inadequate description of grazing management practices or treatments, (2) weak study designs, and (3) lack of pre-treatment data. More long-term, replicated treatment studies are needed in the future.

Cattle diets in the Blue Mountains of Oregon. II. Forests.

Esophagerlly flstulated cows were used on forested range in northeastern Oregon to collect diet samples which were then analyzed by the microhlstological technique. Grasses, forbs, and shrubs averaged 61,16,and 23% of the diet, respectively. Composition of diets differed among years and with seasonal advance. Idaho fescue and elk sedge were the most important forage species consumed. Forbs were used heavily in the early part of the grazing season before maturation. Browse comprised as much as 47% of the diet when green grass was unavailable. Cattle were opportunistic grazers and did not limit their selection to grass species. On forested ranges cattle diets varied among grazing periods within each year as well as among years. Knowledge of dietary habits of livestock and game animals is valuable to the range manager in determining if competition exists among different range animals and in balancing livestock and game numbers with available forage. Also, a knowledge of species consumed tells a manager what the key species are and helps explain changes in diet quality and animal performance (Holechek et al. 1981). At present information concerning cattle diets on forested range in eastern Oregon is limited to utilization studies reported by Pickford and Reid (1948), Harris (1954), Miller and Krueger (1976), and Skovlin et al. (1976). Pickford and Harris (1948), Harris (1954), and Skovlin et al. (1976) conducted their research at the Starkey Experimental Range and Forest in northeastern Oregon. Results from all three studies showed that bluebunch wheatgrass (Agropyron spicufum), Idaho fescue (Festuca iduhoensis). prairie junegrass (Koeleriu cristata), elk sedge (Carex geyeri), Sandberg bluegrass (Pea sandbergii). and pinegrass (Calumugrostis rubescens) were the primary forage species considering availability and utilization. Pickford and Reid (1948) reported that grass was the primary forage class consumed by cattle but forbs were readily utilized in June and early July. Shrubs, particularly common snowberry (Symphoricarpos albus), also received heavy use during some periods although shrubs comprised a small amount of the available forage. Harris ( 1954) observed that over a 9-year period bluebunch wheatgrass was the forage species most heavily used by cattle followed by prairie junegrass, Idaho fescue, elk sedge, and pine. grass. Skovlin et al. (1976) also found that bluebunch wheatgrass was an important forage species. Elk sedge and pinegrass, however, contributed the most forage. In all three of the previously discussed investigations, Sandberg bluegrass (Poa sandbergii) was one of the most common forage species present but utilization Authors were, respectively, graduate research assistant: associate professor rangeland msources, Oregon State University, Eastern Oregon Agricultural Research Center, Union. Oregon; professor, project leader, U.S. Dep. Agr. Rangeand wildlife Habitat Laboratory, La Grandc, Oregon; and leader, rangeland resources progran+ Oregon State University, Corvallis, at the time of the research. J.L. Holechek 1s currently assistant professor of range science, Division of Animal and Range Sciences, New Mexico State University, Las Cruces, New Mexico 88003. This report is Oregon State Agricultural Experiment Station Technical Paper Number 5490. This research was jointly funded by the Eastern Oregon Agricultural Research Center, Oregon State University and the Pacific Northwest Forest and Range Experiment Station, United States Forest Service, U.S. Dep. Agr., and was part ofthe PNWFRES Project 1701 entitled,“Theinfluenceofcattlegrazmgmethods and big game on riparian vegetation, aquatic habitat and fish populations.” levels were much below those for bluebunch wheatgrass, prairie junegrass, Idaho fescue, and elk sedge. Pickford and Reid (1948) observed cattle during the grazing season and reported a preference for grasslands. Forest areas were generally utilized by mid-summer. However, Harris (1954) stated that cattle used forest areas all summer when heat and/or flies became intense, although a preference for grassland areas were shown. In these studies cattle grazed an 8500-ha range area divided into two pastures and grazed under deferred rotation. The objectives of this study were to restrict cattle to forest ranges and determine important dietary constituents, estimate changes in diet with season progression and to observe annual differences in dietary constituents. Experimental Site and Procedure The study was conducted on a portion of the Starkey Range described by Holechek et al. (1981). In 1976, two 230-ha pastures were established on a range having a common grazing history. The vegetation and terrain of the two pastures was similar. Vegetation is representative of the ponderosa pine-Idaho fescue (pinus ponderosa-Festuca idahoensis), ponderosa pine-common snowberryelk sedge (Pinus ponderosa-Symphoricurpos albusCurex geyeri), Douglas fir-ninebark (Pseudotsuga menziesiiPhysocarpus malvuceus), and Douglas fir-common snowberryelk sedge (Pseudotsuga menziesii-Symphoricarpos albus-Curex geyeri) associations originally described by Daubenmire and Daubenmire (1968). Percent cover of important forage species on the pasture was determined and presented in Table I. Because the vegetation composition on the two pastures was identical,, cover data were pooled across pastures. Scientific and common names in Table 1 and the text follow Garrison and Skovlin (1976). Cattle grazing was conducted on the pastures in 1976, 1977, and 1978 under a two pasture-one herd rest rotation grazing system. This involved grazing one pasture all season long in 1976 and resting the other pasture. In 1977 grazing was initiated on the pasture rested in 1976. At mid-season cattle were moved to the other pasture. In 1978, the pasture rested in 1976 was grazed while the other pasture was rested the entire season. Grazing was initiated on June 20and concluded on October JOinall three years of study. Diet samples were collected with four esophageally fistulated cows in all three years of study. Eighteen head of yearling heifers and four fecal collector steers were also grazed on the pastures. Data on diet quality, forage intake, and livestock performance are given in Holechek et al. (198 1). Two collections were made every other week with thet ftstulated animals. The grazing season was divided into four 28-day periods to show trends in dietary botanical composition. These were June 20 to July 18 (late spring), July 19 to August 15 (early summer), August 16 to September 12 (late summer), and September 13 to October 10 (fall). Sixteen esophageal fistula samples were collected during each period. Diet samples were analyzed for botanical composition by the Sparks and Malechek (1968) method. Where applicable, regresJOURNAL OF RANGE MANAGEMENT 35(2), March 1992 239 Table 1. Percent cover of the primary forage species and their percent by weight contribution to cattle diets. Snecies Percent Percent cover’ in diet* Bluebunch wheatgrass (Agropyron spicatum) Elk sedge (Carex geyeri) Pinegrass (Calamogrostis rubescens) One-spike danthonia (Danthonio unispicota) Idaho fescue (Festuca idahoensis) Western fescue (Festuco occidentalis) Kentucky bluegrass (Poa prorensis) Sandberg bluegrass (Poa sandbergii) Total grasses Western yarrow (Achilles millefolium

Nutrient quality of bluebunch wheatgrass regrowth on elk winter range in relation to defoliation.

Effects of defoliating bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. & Smith) to increase the quality of regrowth available on Rocky Mountain elk (Cervus elaphus nelsoni Bailey) winter range were studied from 1988 through 1990. Percent calcium, phosphorus, in vitro dry matter digestibility (IVDMD), and available forage (kg/ha DM) of regrowth present on control, spring-defoliated, and fall-defoliated plots were determined in November of 1988 and 1989, and April of 1989 and 1990. Spring conditioning did not affect the percentage of calcium and phosphorus, or available forage compared to the current years growth in either November or April. Fall conditioning increased digestibility and increased the phosphorus concentration, but decreased available forage compared to the control and spring-conditioned forage in November. Fall conditioning may create a deficit of forage if regrowth is not achieved. Additional research is needed on defoliation during the early phenological time-period of bluebunch wheatgrass to improve the forage quality of elk winter ranges.

Three methods of determining diet, utilization, and trampling damage on sheep ranges.

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