The purpose of this research was to investigate the effects of climatic variations upon the daily activities of grazing cattle. The activities of individual cows on a partially seeded salt desert shrub range were observed and recorded during three grazing periods. Two of the periods were during consecutive winters and the other during the spring. Climatic variations during the second winter period were quantified and compared to changes in the daily activity patterns of the cattle. Distinctly different daily routines of cattle activities were evident for the winter and spring seasons. In the spring, the cattle grazed, traveled, and drank more each day than they did during the winter months. The increase in these activities was attributed to the more temperate climatic conditions and the higher energy demands of lactation. Air temperature, changes in barometric pressure, windspeed, precipitation, snow depth, and radiation all influenced cattle activities in the winter. Decreasing air temperature and rapid fluctuations in barometric pressure both correlated significantly with increased grazing time. Increasing windspeed and greater snow depth caused the cattle to travel less distance daily. The cattle ceased grazing during snowstorms. They oriented themselves at right angles to the sun while standing and lying. The modifications which occurred in daily activity patterns were shown to be apparently directed toward the conservation of energy during periods of climatic stress.

The effect of seasonal cattle grazing on a newly reintroduced population of California bighorn sheep (Ovis canadensis californiana) in Big Cottonwood Canyon, Idaho, was studied. The hypothesis that bighorn sheep avoid cattle was tested. The issue of avoidance between bighorn sheep and livestock is arguable. Some studies have found that bighorn sheep avoid cattle while others have found no response of bighorn sheep to cattle. Evidence was found to document the avoidance of cattle by bighorn sheep. The size of the bighorn's home range and core area decreased with the movement of cattle into areas of high bighorn use. As cattle were moved into bighorn core areas, sheep responded by relocating. Bighorn sheep decreased their distance to escape terrain as cattle moved closer. The level and location of human disturbance on the study area did not have any effect on bighorn sheep movements or how sheep used the habitat. The severity of response observed is in marked contrast with the response of established bighorn populations to cattle. I suggest that newly reintroduced bighorn sheep are extremely sensitive to disturbance as a result of relocation trauma. Sensitivity may diminish over time.

The mountainous ranges of the West are commonly used during the summer and have been used in this manner since the settlement of white men over a century ago. Many of these ranges have been mis-managed and are in poor condition. The productivity of these ranges greatly affects the economy of the nation; thus, if ranges in poor condition have a nutritive value lower than ranges in good condition, it results in an economic loss. little work has been done to determine the nutritive value of mountainous summer ranges in good condition compared to similar ranges in poor condition.

Wildfires have caused concern as they have increased in severity and intensity over the last few decades. Land managers have sought management actions to mitigate the risk of wildfire by reducing fuel loads, thus decreasing wildfire intensity. Camp Williams is a National Guard camp near Bluffdale, Utah, where small arms and artillery training occurs. Managers at Camp Williams have created fuel breaks by implementing targeted sheep and goat grazing to remove fine fuel and thin brush. Management objectives set utilization of fine fuels (herbaceous) at 80% by weight. Questions arose regarding the ecological impact of the prescribed grazing rates in these fuel breaks. This study evaluated three fuel breaks and quantified the impacts of targeted sheep and goat grazing at 80% utilization. During the summer of 2015, herbaceous cover, shrub cover, shrub density, and bunch grass density was collected along eight paired (inside fuel break and outside fuel breaks) transects. Results indicate that the current management grazing plan could lead to an increase of invasive annual grasses, which may be counterproductive in fuel breaks. Often fine fuel treatments rely on high levels of grazing utilization (> 80%). However, high levels of utilization can lead to ecological degradation by reducing or eliminating native bunchgrasses. The objectives of the second study conducted were to determine how different levels of grazing utilization (30%, 50%, and 80%) relate to fuel characteristics and subsequent fire behavior. Results suggest that moderating grazing utilization levels (50%) may allow for more sustainable fuel reduction treatments while still reducing wildfire risks.

A series of grazing trials were conducted on high elevation summer range near Cedar City, Utah . Cattle and sheep were stocked alone and in common in .4 hectare (ha) paddocks. Stocking rates were .76 ha/AUM in 1981 and .60 ha/AUM in 1982. Vegetation measurements were taken before and after grazing treatments to quantify vegetation disappearance. Diet samples were collected from esophageally fistulated sheep in the paddocks before grazing treatments were applied. After a predetermined level of forage utilization was achieved, the paddocks were re-sampled by the esophageally fistulated sheep to examine diets consumed from the forage-reduced vegetation. Behavioral observations were made throughout the trials on sheep grazing alone and with cattle. The length of time sheep spent at a feeding station, feeding station interval, was measured. Sheep ate less grass and more forbs and shrubs than cattle. Cattle showed a strong reluctance to browse snowberry (Symphoricarpos oreophilus) even when the herbaceous vegetation was greatly reduced. Utilization of grasses, forbs and shrubs in the common use paddocks did not represent an average of the utilization by cattle and sheep each grazing alone. Cattle and sheep grazing together used more forage, especially snowberry, than calculated from single use averages. The diets of esophageally fistulated sheep were altered by the various grazing treatments. Diets consumed from previously ungrazed paddocks were higher in forbs, in vitro organic matter digestibility (IVOMD) and crude protein (CP) and lower in fiber than those diets consumed after paddocks had been grazed. Sheep consumed diets higher in IVOMD but lower in CP in paddocks previously grazed by sheep than where cattle had grazed alone or in commonly grazed paddocks. Sheep selected diets from the remaining herbaceous layer when grazing after sheep but ate mostly snowberry when grazing after cattle. Diets of sheep consumed subsequent to common use grazing were intermediate containing both snowberry and grasses. Sheep adjusted their feeding behavior as the grazing trials progressed by increasing the number of brief feeding station intervals. This trend was consistent regardless of whether sheep grazed alone or in common with cattle. However, when sheep grazed with cattle, longer feeding station station intervals persisted further into the grazing trials indicating that amounts of acceptable forage per feeding station were not reduced as quickly as when sheep grazed alone.

A ten-paddock short duration grazing cell was stocked with yearling heifers at a stocking rate of 0.7 ha per animal unit month and a stocking density of 0.14 ha per animal unit. A continuously-season- long-grazed (CSLG) pasture was used as a control. It was stocked at the same stocking rate, but at a stocking density of 1.4 ha per animal unit. Grazing periods in SDG paddocks were two or three days. Dietary quality was assessed by crude protein · content and in vitro digestibility of esophageal fistula estrusa samples. Three variables of ingestive behavior were measured, including ingestion rate, biting rate, and grazing time. Daily forage in take was estimated by multiplying ingestion rate by grazing time. Animals in CSLG gained significantly more weight in 1983, no statistical differences were detected in 1984, and, in 1985, animals gained more in SDG. No differences were detected in diet quality between SDG and CSLG throughout the study. No treatment differences were de tee ted in ingestive behavior variables in 1984, but ingestion rate was significatantly higher and grazing time significantly less in SDG during 1985. Differences in diet quality and ingestive behavior be tween SDG and CSLG at the beginning and end of the grazing season were evaluated for indications of possibly extending the season of nutritious forage. Such differences were few and inconsistent. Daily changes in diet quality and ingestive behavior during the grazing period within SDG paddocks were large. Diet quality declined significantly during the grazing period in all three years. Ingestive behavioral responses changed significantly, including declines in ingestion rate and increases in grazing time. Forage in take declined during the grazing period on a particular paddock. A model was developed that related behavioral responses to sward characteristics. Ingestion rate and grazing time were predicted from available biomass and herbage crude protein content. The model indicated that declines in biomass and herbage crude protein content translate into rapid declines in ingestion rate, and thus, forage in take. Based on the system studied, grazing periods in SDG paddocks should be two days or less to maintain high levels of livestock performance.

A quantitative description of the foraging process is necessary for effective planning and execution of intensive grazing schemes. Foraging behavior is defined as having two components: feeding and moving. At intervals the foraging animal walks a number of steps searching for food and then pauses to feed at a new position here termed a feeding station. Five behavioral variables were analyzed under this framework: 1) time spent at a feed ing station; 2) number of bites at a feeding station; 3) steps taken between stations; 4) rate of steps; and 5) foraging time. The experimental design consisted of grazing small adjacent, approximately 7-ha paddocks for periods lasting 8 days. Animals significantly (P<0.01) increased the probability of taking 1 to 2 bites at a station as the season progressed. Regression analysis relating foraging time (in days) on a paddock revealed that the regression coefficients were statistically significant (P<0.05) suggesting that heifers were appreciably increasing foraging time as the grazing periods progressed. Analysis of moving behavior indicated that animals most often took 1 step between feeding stations and moved at approximately the same rate regardless of sward conditions. The significance of the behavioral measurements is discussed.

Two common use grazing trials were conducted during two summer grazing seasons (1978-1979) on a typical shrubby grassland site on the Kolob Terrace, about 20 miles (32 km) southeas t of Cedar City, Utah, at an elevation of about 8500 feet (2600 m). Two animal units of ewes with lambs, or cows with calves, or both were stocked in each of six, one acre (0.39 ha) pastures. A five to one substitution ratio provided two single-species and one mixed (five ewes with lambs and one cow with calf) livestock treatments replicated twice . The pastures were grazed for nine days during which time two major experiments were performed.

I studied the effect of moderate sheep grazing on a shadscale plant community at the Desert Experimental Range, southwestern Utah, USA, using a 61-yr data set with two grazing treatments (yes vs. no), two seasons (spring vs. winter), and two soil types (loamy-skeletal vs. coarse-loamy). I studied precipitation, total species cover, annuals, shrub survival, seedling recruitment, plant succession, and plant spatial relationships./p> Precipitation showed high variability (CV=31%) masking on short-term cycles, resulting in study intervals with average (1935-58), dry (1958-69), driest (1969-75), and wet (1980-94[5]) regimes. Total cover in both grazed and ungrazed pastures increased between 1935 and 1975 before decreasing to 1994. Treatments diverged with time, however, so cover was higher in ungrazed pastures in 1975 and 1994. Individually, Atriplex confertifolia decreased from 1958-94 and Ceratoides lanata from 1975-94. Artemisia spinescens increased in ungrazed pastures from 1935-94, while remaining very low in grazed pastures. Grasses increased from 1935-94 with little grazing effects. Annuals increased from absence in 1935 to 63% frequency in 1994; precipitation may be related to this increase. Grazing and soil type had few long-term or short effects on shrub survival. Similarly, only C. lanata showed a microhabitat effect, with greater seedling survival in vegetated than open patches. Seedling recruitment was positively correlated with precipitation. Only A. confertifolia recruitment responded to grazing; it was higher in grazed pastures. A fuzzy graph analysis showed a moderate grazing effect on succession. Clumped distributions were common and were unaffected by grazing but increased in wet years. Plant establishment occurred disproportionally in sites occupied or formerly occupied by plants, suggesting facilitation. Negative interference, however, was suggested by new recruitment occurring further from larger existing individuals. Moderate grazing had little effect on spatial relationships. In conclusion, the multivariate approach yielded broader conclusions than any individual factors. Although some factors showed more grazing effects than others, grazing could not completely explain observed changes; climate and inherent plant attributes must also be considered. Management at moderate grazing levels may only play a limited role in shadscale communities.

The objectives of this study were to: l) determine the contribution of federal land grazing to beef production in Utah and the 11 western states, and 2) trace the impact of hypothetical incremental reductions in federal land grazing in the 11 western states on total beef supply and retail beef prices in the United States. The federal land animal units in the 11 western states were obtained from Bureau of Land Management and Forest Service records. The animal units were converted into the number of breeding cows and feeder calves totally dependent on federal land grazing, with the help of animal units per breeding cow. The animal units per breeding cow were calculated from a representative stock count chart of a typical 50 cow Utah ranch. The same chart provided percentage proportions of the number of calves and feeder calves. These feeder calves are the animals that originate and are totally dependent on federal lands. The minimum contribution of federal land grazing in the 11 western states to total beef supply in the United States ranges between dressed beef from feeder calves and cull cows on one end, and slaughter animals and cull cows on the other. The actual minimum contribution is somewhere to the middle of these extremes. The hypothetical incremental reductions in federal land grazing were calculated in terms of percentage reduction in the number of cows, calves and feeder calves, and the resultant decreases in beef tonnage on the lower and upper limits of minimum contribution of these lands to total beef supply in the United States. These reductions in beef supply were compared to total United States' beef supply and reductions in total beef supply were estimated in percentage. To estimate the economic and other impacts on individual ranchers, local communities and regional economy, the feed grain in corn equivalents and forage production were compared to livestock and poultry requirements in the 11 western states. It appears that Utah is deficient both in feed grain and roughage production as compared to requirements. The 11 western states as a group were surplus in 1974 in both feed grain and roughage production as compared to livestock and poultry requirements. The contribution of federal lands in roughage production was also estimated. The importance of federal rangelands' contribution, in my study is only 25 percent of total roughage production in the 11 western states and is discussed in the light of other benefits that would be lost if grazing were eliminated from federal lands. Lastly, the impact of reduction in federal grazing in the 11 western states on retail beef prices was estimated by using the concept of price elasticity of demand. It was concluded that an increasingly higher percentage increase in retail prices would occur for given percentage decreases in beef supply (by way of hypothetical incremental reduction in federal land grazing) for increasingly inelastic coefficients of elasticity.