Life Sciences Commons^™

Fractally Sampling Diversity-Environment Relationships To Understand Plant Assemblage Health Across Spatial Scales, Elizabeth G. Simpson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans influence the health of ecosystems and rely on healthy ecosystems to support their livelihoods and well-being. By looking at how the parts of ecosystems interact we can understand and improve ecosystem health. Ecosystem interactions change across spatial scales or different size patches of area. For example, individual organisms interact with each other at small spatial scales, while at large spatial scales, communities of organisms interact with weather conditions. However, many research studies do not look at how ecosystem interactions change across spatial scales. To address this gap in ecological research, I use a fractal sampling design which samples at …

Dairy Breed, Grass-Birdsfoot Trefoil Mixture, And Pasture Nutrition Effects On Intake, Feed Efficiency, And Grazing Adaptation, Michael Greenland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dairy cattle have lower dry matter intake (DMI) on pastures thus leading to less weight gain and milk production than feedlot cows. This study was conducted to determine whether different dairy breeds are better adapted to lower or higher quality pastures as measured in DMI and feed efficiency. The eight treatments consisted of Jersey, Holstein, Holstein-Jersey crossbreds, and 3-breed crossbreds (Montbéliarde-Swedish Red-Holstein) heifers on grass monocultures and grass-BFT mixtures. We observed greater DMI on grass-BFT mixtures. Among breeds, Holstein had the greatest DMI, then the two crossbreds, and Jersey had the least. Feed efficiency was most favorable for Jersey, less …

Greater Sage-Grouse Brood Responses To Livestock Grazing In Sagebrush Rangelands, Hailey Peatross Wayment

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The distribution and abundance of the greater sage-grouse (Centrocercus urophasianus; sage-grouse) have declined in the last 60 years. Range contractions and population declines have been attributed to loss and fragmentation of their sagebrush (Artemisia spp.) habitats. Grazing by livestock remains the predominant anthropogenic land-use across sagebrush ecosystems in North America, occurring on 87% of remaining sage-grouse habitat. Most of the peer-reviewed literature reports the potential for negative impacts of sagebrush reduction treatments, to increase livestock forage, on sage-grouse habitat. However, few studies have linked livestock grazing at the landscape level to vital rates (e.g., nest initiation rates, …

The Effects Of Different Organic Pastures On Dairy Heifer Growth And Development, Jacob A. Hadfield

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Raising dairy heifers in a certified organic setting can be difficult for producers. Conventionally, heifers are raised in a confined setting, and fed a total mixed ration (TMR) that is balanced daily to contain all the needed nutrients for developing heifers. Organic producers can use a TMR in their operations, but due to high organic feed costs, many choose to raise their heifers in pasture-based systems. While pasture-based systems may lower costs, heifers on pasture commonly have lower rates of gain, which can be financially burdensome to producers. Grass-legume pastures may help improve rates of gain in heifers on pasture-based …

Herbage Characteristics Affecting Intake By Dairy Heifers Grazing Grass-Monoculture And Grass-Birdsfoot Trefoil Pastures, Marcus F. Rose

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pasture-based dairies have become more prevalent in recent years due to a higher proportion of organic milk demand and production. Organic certification requires that animals must graze at least 120 days in each growing season. However, dry matter intake is often limited when dairy animals receive most of their herbage from pasture, resulting in lower animal performance and milk production. The purpose of this study was to analyze the complimentary effect of high energy grasses with birdsfoot trefoil (BFT) tannins to improve intake of dairy heifers. Jersey heifers were rotationally grazed for 105 days in 2017 and 2018 on eight …

Impacts Of Cattle Grazing As A Tool To Control Phragmites Australis In Wetlands On Nitrogen, Phosphorus, And Carbon, Brittany L. Duncan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phragmites australis is a plant that is causing problems in wetlands by outcompeting native plants that provide food and shelter for millions of migratory birds. Currently, managers try to control Phragmites australis by spraying herbicide, burning, and mowing, but these methods are costly, time consuming, and have low levels of success. Adding grazing as a tool to control Phragmites australis provides a cheap and low labor alternative. However, there are many concerns regarding if grazing will cause nutrient loading in our wetlands that will decrease water quality and alter beneficial functions of wetlands.

To better understand the effects of grazing …

Modulation Of The Nutritional Context And Early Experience As New Tools To Increase The Use Of Medusahead (Taeniatherum Caput-Medusae Ssp. Asperum) By Grazing Sheep, Juan J. Montes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Medusahead is an invasive weed that reduces wildlife habitat and biodiversity as well as commercial and recreational value of land. Grazing represents a sustainable method for its control but stakeholders claim that livestock will not eat medusahead because of its low feed value. This research explored a supplementation program, along with experiences early in life with mother to enhance use of medusahead by sheep. Results showed that an energy supplement did not enhance medusahead use by sheep but that early experience with mother influenced yearlings to use the weed more evenly across days. When availability of the weed was low …

Mitigation Of Medusahead (Taeniatherum Caput-Medusae) Through Grazing And Revegetation On The Channeled Scablands Of Eastern Washington, Clinton A. Stonecipher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A large portion of the historical steppe and shrub-steppe habitats in eastern Washington have been altered through biotic and abiotic processes resulting in the annual grass medusahead becoming a large component of the altered vegetation. Experiments were conducted to determine: 1) if supplementing cattle with protein would help increase utilization of medusahead, 2) the grass species that could establish in the region, and 3) if mechanical disturbance would aid in such revegetation efforts. Cattle grazing medusahead-infested rangeland increased consumption of medusahead after all forage matured due to a reduction in the quality of forage alternatives. Cattle supplemented with protein increased …

Influence Of Fall Grazing By Sheep On Plant Productivity, Shrub Age Class Structure And Herbaceous Species Diversity In Sagebrush Steppe, Ryan Duncan Woodland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traditional chemical and mechanical treatments of Wyoming Big Sagebrush (Artemisia tridentata ssp. wyomingensis) are costly and have typically focused solely on increasing forage for livestock production. Managing these systems biologically with grazing can potentially reduce costs and increase both biodiversity and understory production as well as rejuvenate Wyoming Big Sagebrush (ARTRWY). This experiment was conducted on Deseret Land and Livestock Ranch in northern Utah in October 2003. One hundred and twenty sheep (dry ewes) grazed 3, 60m x 40m plots (40 sheep plot^-1). Sheep were provided a protein-energy supplement to facilitate use of the secondary metabolites …

The Influence Of Predator Exclosures And Livestock Grazing On Duck Production At Bear River Migratory Bird Refuge, Utah, Benjamin C. West

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nest predation is a major factor impacting duck production and recruitment on breeding areas in North America. I surveyed waterfowl managers employed by the U.S. Fish and Wildlife Service and U.S. state wildlife agencies to determine their beliefs about nest predation and its management. Over 64% of respondents believed that rates of nest success on their management units averaged < 30% between 1996-2000. Managers believed habitat management and direct predator control were the most effective techniques to reduce nest predation. The construction of predator ex closures around nesting habitat also has been recommended to reduce nest predation. Between 1999-200 I, I evaluated the effectiveness of 4 predator ex closures to enhance duck nest success at Bear River Migratory Bird Refuge, Utah. During this period, rates of nest success in the exclosures were slightly higher than that within control plots, but still < 15%. Although published guidelines commonly recommend predator fences < 117 cm in height, I observed red foxes jump the 11 4-cm-high fences. Additional research is needed to identify effective predator fence designs.

Wildlife managers have argued that periodic disturbance of vegetation should be a component of management on waterfowl breeding areas. Although many techniques are available to manipulate vegetation, grazing by domestic livestock has been controversial. Some researchers have reported that livestock grazing …

Recreation, Livestock Grazing, And Protected Resource Values In The Grand Staircase-Escalante National Monument, Lael Palmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis reports the results of a project which identified differences in characteristics of Grand Staircase-Escalante National Monument user groups as they related to their perceptions of how they experience the Monument as recreationists. It explored opinions of four groups: hikers vs. hunters and pre-designation users vs. post-designation users. Responses of these groups were compared for attribution of perceived resource damage, feelings of crowding, acceptability of management action, and importance of identified monument values to their visit. In addition, characteristics of the users were examined to determine if demographic characteristics accounted for differences in perception toward the resources. Finally, how …

Influence Of Grazing, Fire, And Rainfall Regime On Plant Species Dynamics In An Ethiopian Perennial Grassland, Michael J. Jacobs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The dominant habitat-type of Omo National Park (ONP), Ethiopia, is grassland. This grassland supports a variety of wild herbivores and indigenous people; the latter hunt large herbivores for subsistence or graze their domestic livestock in the Park. Therefore, an understanding of grassland dynamics is a high priority for ONP management. Grazing and fire are major factors influencing species composition and vegetation change in East African grasslands. Rainfall regime, in turn, can influence both grassland response to grazing and fire. The ONP grasslands occur along a rainfall gradient ranging from subhumid to semiarid. Research objectives were to: (1) test the Milchunas, …

Autecological And Grazing Control Studies Of Dyers Woad (Isatis Tinctoria L.) On Northern Utah Rangelands, Kassim O. Farah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dyers woad (Isatis tinctoria L.) is a noxious weed on northern Utah rangelands. Chemical and mechanical means of control are unsuitable for rangelands. A potential alternative, biological control, is difficult due to a lack of basic ecological information. To remedy this, some aspects of the population biology and autecolgy of dyers woad were studied. The feasibility of controlling dyers woad by early spring grazing was also investigated via clipping experiments.

A population study followed the survivorship of experimentally established populations over two years. Fall germinating individuals (1984) overwintered as rosettes twice and all survivors reproduced successfully. Spring germinating individuals …

Utilization Of Crested Wheatgrass Plants By Cattle Under Several Grazing Regimes, Patricia Selann Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Patterns of grazing on individual crested wheatgrass plants were studied using scale maps of plant basal outlines within randomly located plots. The occurrence and extent (part of plant grazed, stubble height) of grazing on each plant was recorded on the maps at two and three day intervals throughout a grazing treatment. Allometric equations for estimating phytomass from plant photosynthetic volume were generated using nonlinear regression analysis. Equations were specific to year. The percent weight remaining in the stubble of a grazed plant was estimated using a second-order polynomial equation relating cumulative percent plant height to cumulative percent plant weight. A …

Animal Nutritional Response To Sward Structure Under Short Duration Grazing Management, Kenneth C. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 …

Effect Of Short Duration Grazing On Soil Moisture Depletion And Plant Water Status In A Crested Wheatgrass Pasture, Jon M. Wraith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A short duration grazing system was utilized to determine the effects of intensive periodic defoliation during spring on soil moisture depletion patterns and plant water status in a crested wheatgrass (Agropyron cristatum and A. desertorum) pasture in central Utah. Exclosures were constructed to compare grazed and ungrazed responses. Soil moisture was monitored to a depth of 193 cm at one to two week intervals from mid-April to late-September using a neutron moisture gauge. Predawn and midday leaf water potentials were estimated using a pressure chamber technique. The two paddocks included in the study were grazed three times between …

Locoweed Poisoning In Cattle: An Overview Of The Economic Problems Associated With Grazing These Ranges, John E. Barnard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Locoweed poisoning, caused by ingestion of certain species of Astragalous and Oxytropis, has had serious economic impacts through a loss of productivity in livestock. This study has attempted to evaluate losses suffered by livestockmen grazing their cattle on areas infested with locoweed species. The results indicate a serious economic impact on these individuals.

Personal interviews were carried out with five cattle ranchers faced with typical locoweed problems. These beef cattle operations were located in Utah, Wyoming, and New Mexico. All of these producers described similar problems and losses due to locoweed poisoning. Information obtained from these interviews was used …

The Economic Impact Of Potential Changes In Federal Grazing Policies On Ranchers In Wayne County, Utah, Kib Elden Jacobson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to select an area in Utah that was predominantly livestock oriented which used federal lands for livestock grazing, and to develop model ranches exemplifying the typical live-stock operation in the area. These model ranches were then used in a Budget Generator Program (BG) and a Linear Programming framework (LP) to simulate reductions of 25%, 50%, 75% and 100% reductions of BLM land usage. The results were then used to determine income changes, herd size changes, and resource usage in the models as the reductions took place.

The area chosen was Wayne County, Utah because …

The Energy Expenditure Of Heifers Grazing Crested Wheatgrass Rangeland In West-Central Utah, Kris M. Havstad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The free-roaming ruminant requires energy for the demands of vii grazing, traveling and thermoregulation that are not required by its confined counterpart. Literature estimates of these additional costs range from 10 to 170 percent above maintenance. The uncertain magnitude of this increased demand and the factors that contribute to it impede the ability of the rangeland ruminant nutritionist to establish guidelines for the energy requirements of the free-roaming herbivore. This study was designed to estimate the energy expenditure of yearling Angus heifers while grazing a declining supply of available crested wheatgrass forage (Agropyron cristatum) on rangeland in west-central …

Economic Impacts Of Public Grazing Reductions In The Livestock Industry With Emphasis On Utah, Deevon Bailey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this paper was to determine the immediate impact of reductions in public grazing on livestock production in the United States. This was accomplished by the use of linear programming techniques. Different grazing reduction simulations were utilized to determine the short and long run effects of across-the-board reductions in public grazing.

The United States was divided into 13 regions. The 11 western states were considered as individual regions. Special emphasis was placed on the effects of grazing reduction on Utah. The availability and utilization of feed and livestock products during a "normal year", 1978, were considered in this …

Forage Selection And Nutrition Of Sheep And Goats Grazing In The Tunisian Pre-Sahara, Rudolfo Ricardo Griego

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nomadic pastoralism has been the traditional method of utilizing grazing resources in arid and semi-arid regions of Africa. However, increased sedentarization accompanied by growing human and animal populations during the past two decades is thought to be accelerating the desertification process, or desert expansion. The specific interactions of the grazing animal with this process has been speculated upon but not studied in detail. A comparative study was initiated during the spring grazing season of 1974 to determine sheep and goat nutritional and production responses, as well as patterns of vegetative selection and utilization under the pastoral system currently employed in …

The Relationship Of Climatic Factors To Grazing Activities Of Cows On Winter And Spring Ranges, Benton M. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 …

Determining Market Areas For Livestock Grazing, Robert G. Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Differentials between rancher costs of operating on private and public range were studied in an attempt to define market areas for livestock grazing in western United States.

The problem of defining market areas is basically a problem of grouping differentials between rancher costs of grazing on private leased range and National Forests that are reasonably homogeneous and statistically testing differences among means of the different groups.

Several methods were used to group forests with reasonably uniform differentials into market areas for cattle. A grouping of forests which have the same average grazing fee does not, however, yield market areas which …

The Effect Of Range Condition And Intensity Of Grazing Upon The Daily Intake And Nutritive Value Of The Diet Of Sheep On Summer Ranges Of Northern Utah, Merwyn Mortimer Kothmann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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.

The Influence Of Nitrogen And Phosphorus Supplements On The Composition Of The Ruminal Ingesta Of Sheep Grazing Desert Range Forage, James G. Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Approximately 46 million acres or 88 per cent of the land area of the state of Utah has been classified by Reuss and Blanch (1951) as "range land open for grazing." Although some of this area cannot be grazed because of inaccessibility, lack of water, poison plants, and similar factors, it is estimated that some 40 million acres or 78 per cent of the total land area is available for grazing. Most of this grazing land is federally owned (73 per cent), while only 22 per cent is privately held, and 5 per cent is state owned.

Economics Of Managing State-Owned Grazing Lands, Lowell Ray Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Range land is an important resource in Utah's economy. Of 52.7 million acres of land in Utah about 78 percent is used for production of range livestock (14).¹ In 1958, cash receipts of range livestock amounted to 62.7 million dollars, or 38.8 percent of Utah's total agricultural cash receipts (19).

Of total land within its boundary, the state owns 2,723,157 acres, or 5.17 percent (32). The state legislature has designated the Utah State Land Board as the responsible agency for administering this land to provide income for various state institutions.

The people of the state of Utah are required …

Some Of The Relationships Between Livestock Grazing And Duck Nesting In The Saltgrass Vegetation Type In Utah, Horatio W. Murdy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Little is known of the relationships between livestock grazing and duck nesting. This dearth of information occurs in spite of the fact that an understanding of these relationships is necessary in order to evaluate duck production on range land, and to formulate grazing policies for lands devoted to the production of ducks.

Recognizing the need for information on this subject, the Utah Cooperative Wildlife Research Unit and the Wildlife Management Institute jointly sponsored a study, during 1948-1949, of livestock grazing-duck nesting relationships in the saltgrass vegetation type in northern Utah. The study was financed by the Institute and supervised by …

The Ecology Of Agropyron Inerme On Protected And Heavily Grazed Range Land In Cache Valley, Utah, Wallace R. Hanson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the past decade much attention has been attracted to the great range lands of the West. The inherently low productivity of these arid lands coupled with abnormal drought and constantly heavy use by livestock because of lack of grazing control, have caused these lands to become greatly depleted over most of the West. That the vegetation on most range land in the intermountain states is depleted appreciably is evident to the careful observer. Undoubtedly the vegetation of much of the range has decreased in quantity, but more serious in many cases is the decrease in quality. Valuable forage species …

The Ecology Of Agropyron Inerme On Protected And Heavily Grazed Range Land In Cache Valley, Utah, Wallace R. Hanson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the past decade much attention has been attracted to the great range lands of the West. The inherently low productivity of these arid lands coupled with abnormal drought and constantly heavy use by livestock because of lack of grazing control, have caused these lands to become greatly depleted over most of the West. That the vegetation on most range land in the intermountain states is depleted appreciably is evident to the careful observer. Undoubtedly the vegetation of much of the range has decreased in quantity, but more serious in many cases is the decrease in quality. Valuable forage species …