• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 374
  • 252
  • 67
  • 28
  • 26
  • 15
  • 15
  • 15
  • 6
  • 6
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 993
  • 170
  • 133
  • 122
  • 121
  • 101
  • 87
  • 81
  • 78
  • 74
  • 69
  • 67
  • 65
  • 57
  • 55
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Application of Electrified Fladry to Decrease Risk of Livestock Depredations by Wolves (Canis lupus)

Lance, Nathan J 01 May 2009 (has links)
Wolf (Canis lupus) predation on livestock can cause economic and emotional hardships for livestock producers, complicating the balance of wolf conservation with other human interests. New management tools that decrease risk of predation may offer additional flexibility or efficiency for both livestock producers and management agencies. I examined 1) the efficacy of electrified fladry compared to fladry at protecting a food source from wolves in captivity, 2) the efficacy of electrified fladry for reducing wolf use of pastures and preventing depredations, and 3) the applicability of electrified'-fladry. In captivity I tested the reaction from 15 groups (46 wolves) to the presence of fladry, electrified fladry, or no barrier within their enclosures. During trials, a deer carcass was provided in one corner of the pen, and a strand of fladry (n = 5 pens), or electrified fladry (n = 5 pens), was strung across the pen to protect the food resource. Failure of the barriers was defined by at least one animal in a group moving across the barrier. Both fladry and electrified fladry effectively excluded wolves from a food resource for short durations of time (1'-14 days), but electrified fladry was more effective. My research indicated that although electrified fladry has the potential to reduce wolf depredations, animal learning, motivation, and personality play critical roles in the effectiveness of fladry systems. In Montana, I assigned 9 livestock operations to randomly receive a treatment (electrified fladry, n=6 pastures) or control (not receiving electrified fladry, n=6 pastures). I measured cost per kilometer for purchasing materials, number of people and hours required for installing and maintaining, as well as recording observations of potential difficulties with electrified fladry. I formed and distributed an exit'-survey to each rancher who participated in the study to assess opinions about the use of the technique. Wolf activity at the ranches was insufficient and I was not able to determine if electrified fladry was successful or unsuccessful for preventing livestock depredations. I found, however, that electrified fladry may be limited by costs associated with its purchase and that the application and effectiveness of electrified fladry may limit its usefulness for addressing wolf'-livestock conflict. The understanding of human perceptions of management tools is critical to determining the success of implementing management techniques and fostering participation and cooperation among stakeholders.
322

Seed Dispersal by Livestock: A Revegetation Application for Improving Degraded Rangelands

Gokbulak, Ferhat 01 May 1998 (has links)
A series of experiments was conducted to: 1) investigate how feeding cattle with different amounts of different-sized seeds affects seed passage rate through the digestive tract, and the germinability of passed seeds; 2) examine how the location of seeds in dungpats of different thicknesses influences seedling emergence , development, and survival in cattle dungpats; and 3) characterize seedling emergence in naturally and artificially deposited cattle dungpats . Three perennial , cool-season grasses, bluebunch wheatgrass [Psuedoroegneria spicata (Pursh) A. Love], Sandberg bluegrass (Poa secunda Presl.), and 'Hycrest' crested wheatgrass [Agropyron desertorum (Fisch. ex Link) X A. cristatum (L.) Gaert.], were used as representative revegetation species for the Intermountain West region. When cattle were fed 60,000, 30,000, 15,000, and 7,500 seeds of bluebunch wheatgrass and Sandberg bluegrass, the recovery of passed seeds for both species declined as seed feeding levels decreased from 60,000 to 7,500 seeds per animal and as time after seed ingestion increased from 1 to 4 days. Sandberg bluegrass seeds had greater germinability than bluebunch wheatgrass seeds at all seed feeding levels and collection dates. In complementary greenhouse studies, artificially prepared cattle dungpats (20 cm diameter) with different thicknesses (1, 2, and 4 cm) were placed on a sandy loam soil (initially at field capacity) in large plastic containers. Pre-germinated seeds of blue bunch wheatgrass, Sandberg bluegrass, and/or Hycrest crested wheatgrass were planted separately in the center and periphery of dungpats at heights (from bottom of dungpats) of 0.5 cm for 1-cm-thick dungpats, 0.5 and 1.5 cm for 2-cm-thick dungpats , and 0.5, 2.0, and 3.5 cm for 4-cm -thick dungpats. Half of the dungpat treatments received no supplemental water while the other half received additional water simulating a wet spring . After 60 days, seedling emergence, development , and survival for all species were greatest at the 0.5 cm planting height , regardless of dungpat thickness , and greatest in 1 cm-thick dungpats , regardless of planting height. Seedling emergence , development , and survival were greatest for Hycrest crested wheatgrass, followed by bluebunch wheatgrass and Sandberg bluegrass. In a field study, cattle dung containing passed seeds of blue bunch wheatgrass, Hycrest crested wheatgrass, and Sandberg bluegrass was formed into artificial dungpats (2 kg in mass) with thicknesses of 1, 2, and 4 cm, and respective diameters of 40, 28, and 20 cm, and deposited on bare soil. Cattle also deposited natural dungpats varying in mass, thickness, and diameter. Seedling emergence for all species decreased as artificial dungpat thickness increased from 1 to 4 cm, and was lowest in natural dungpats. Seedling emergence for all dungpat types was greatest for Hycrest crested wheatgrass, followed by Sandberg bluegrass and bluebunch wheatgrass. These studies indicate that: 1) cattle should be fed about 60,000 seeds ( of these grass species) per animal to pass sufficient germinable seed to establish at least one seedling in a dungpat; and 2) seedling emergence, development, and survival in cattle dungpats are greatly influenced by plant species (seeds) ingested, thickness of dungpats, seed location in dungpats, and moisture content of the soil underlying dungpats.
323

An Epidemiological Survey of Avian Tuberculosis in Livestock, Poultry, and Wild Birds in Rich County, Utah

Carver, Royal Thair 01 May 1969 (has links)
A study was conducted in Rich County, Utah to determine the extent of avian tuberculosis in livestock, poultry and wild birds. Sensitivity was elicited in cattle, swine and chickens by tuberculin testing. The Mycobacterium avium organism was obtained from tissues and specimens of cattle, swine, goats, chickens, magpies and sparrows. Methods of eradication of avian tuberculosis and the relationship of avian tuberculosis to mammalian tuberculosis are discussed.
324

A Study of Mineral Nutrition of Range Cattle in Southeastern Utah

Raleigh, Robert J. 01 May 1954 (has links)
General Problem Cattlemen of south central Utah in Sevier and Wayne County areas have been plagued for the past twenty-five or thirty years by a malady known to the cattleman as "Brisket Disease." It is a chronic disease affecting both male and female of all ages. It is characterized in advance stages by enlargement of the brisket and throat regions, loss of appetite, a general unthrifty condition and marked ascites. The seriousness of the disease is indicated by a morbidity rate varying from one to five percent of the cattle grazing these areas with almost one hundred percent mortality rate. Many of the people of these southern Utah counties depend largely on livestock for their livelihood. In order for the livestock industry of these counties to operate as an economical and profitable enterprise, a better performance of the animals on summer ranges and a decrease in the death loss must be obtained. Scope The information contained in this thesis is the result of observation and data collected from the cattle grazing on 7-mile, U. M, and Sheep Valley Ranges, during the summers of 1948 through 1953. The work reported consists of forage analyses, blood analyses, liver biopsies, gross and histopathological studies of the tissues of affected animals. Controlled experiments were carried out to note if mineral supplements would prevent the disease. The sick animals were treated on the range at the same elevation to see if they could be cured. Purpose The purpose for undertaking the study was to determine the etiology and nature of the disease as it is manifested by symptoms and pathology; and to develop methods of treatment and control.
325

Adoption of Range Management Innovations by Utah Livestock Producers

Didier, Elizabeth Anne 01 May 2002 (has links)
Recent years have seen changes in ecological conditions, ownership patterns, and political-legal forces that affect the sustainability of Western range livestock production. Enterprise diversification and implementation of improvements are advocated as ways for ranchers to cope with marginal returns from ranching while better managing resources. However, relatively few ranchers make such substantive changes in their operations, and previous research suggests that rates of adoption may be especially low in Utah. Using a qualitative approach, this study explored innovation adoption among Utah ranchers. During preliminary interviews with 13 key informants, commitment to traditional ranching lifestyles, the state's settlement pattern, and availability of time and capital were identified as barriers to adoption. In-depth interviews were then conducted with 15 producers known within the ranching community for innovative management. Objectives of these interviews were to identify personal characteristics of the respondents, preferred information sources, and motivations for and barriers to adoption. Most respondents were ranching full-time on multi-generation, family ranches, and living on or very near the ranch. Respondents innovate in order to improve profitability, environmental quality, and relationships with resource management agencies and to demonstrate good environmental stewardship to the public. Interaction with extension agents and ranching organizations was common and affected the perceived risk associated with adoption. Motivation to maintain the ranch may be especially strong among interviewees: Each respondent reported being committed to ranching for his lifetime, and in most cases, the ranch is expected to remain in the family for at least one more generation. Individuals who are less dependent on public land and more dependent on ranching income may be more likely to adopt innovations. Even among innovative ranchers, the availability of time and capital as well as commitments to tradition impeded adoption. Unexpectedly, characteristics of the political-legal system in which ranchers operate emerged as barriers to innovation. This research illustrates how the existing innovation adoption framework applies to ranchers, but also defines new theoretical components.
326

Blood Vessel Development and Organization in the Prepubertal Calf Mammary Gland

Hardy, Nicole Rebecca January 2020 (has links)
No description available.
327

Foraging behaviour of ruminant and non-ruminant grazers as a function of habitat heterogeneity in Telperion and Ezemvelo Nature Reserves(Ezemvelo section)

Hamunyela, Ndamonenghenda January 2017 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Resource Conservation Biology. Johannesburg, 29 May 2017. / An understanding of animal foraging behaviour is key to proper management strategies that ensure the survival and species persistence within nature reserves. Here the foraging behaviour of ruminant (hartebeest and wildebeest) and non-ruminant (zebra) grazers were observed and compared between two areas with distinctively different vegetation structure, the natural vegetation (NL) and previously cultivated land (PCL), in Telperion and Ezemvelo Nature Reserves (TENR). Natural vegetation was dominated by tall grass of low greenness with patches of short to very short grass, while the PCL was dominated by areas of very short to short grass (grazing lawns) with patches of medium to tall grass. Step rate (SR) and foraging time spent per feeding station (FTFS) were used as indices of foraging behaviour. I also measured the characteristics of the grass sward (grass height and greenness) grazed on by the three species. Both ruminants had high SR and low FTFS. Despite having similar SR and FTFS, ruminants grazed on grass of different height. Hartebeest preferred tall grass with low greenness content (0-10%), while wildebeest preferred short to very short grass and were significantly selective of areas with relative high greenness (11-50%) on PCL, more so than any other species. Compared to ruminant grazers the non-ruminant (zebra) had low SR and high FTFS and like hartebeest they grazed on medium to tall grass of very low greenness content (0 10%). This study did not reveal any difference in feeding behaviour within species between the two study sites. The finding of this study confirms that ruminant and non-ruminant species have different foraging behaviour, and habitat heterogeneity is necessary for the reserve to support different grazing species. Key words: digestive physiology, feeding station, step rate, wildebeest, hartebeest, zebra / GR2018
328

Teaching unit on livestock loss prevention for agricultural education.

Jones, Robert Carroll 01 January 1953 (has links) (PDF)
No description available.
329

The effects of grazing cover crops on animal performance, soil characteristics, and subsequent soybean production in east-central Mississippi

Bass, Bronson Scott 10 December 2021 (has links) (PDF)
Integrated crop-livestock systems (ICLS) incorporate cropping systems and livestock production by grazing cover crops. With a growing awareness in recent years regarding agricultural sustainability, these systems have begun to be re-introduced into the southeastern U.S. This study evaluated cover cropping systems under grazed no-till (GNT), un-grazed no-till (UNT), and un-grazed conventional tillage (UCT) management, in Mississippi. Beef cattle (Bos spp.) performance was significantly less in the cover crop treatment of oats (Avena sativa) + crimson clover (Trifolium incarnatum) + radish (Raphanus sativus; OCR) in both average daily gain (ADG; 3.03 lb hd-1 d-1) and total gain ac-1 (GAIN; 346 lb ac-1). Soybean (Glycine max) yield was unaffected by cover crop treatment and tillage. The lowest expected economic return was generated by OCR ($749.31 ac-1). Soil penetration resistance was unaffected by the influence of grazing. The greatest concentrations of soil organic carbon (1.44%) and soil nitrogen (0.20%) were observed in GNT.
330

Barriers to Success: Sheep and Goat Producers in the Service-Grazing Industry

Campbell-Craven, Erin A 01 June 2020 (has links) (PDF)
Service-grazing is a novel term for grazing done on land not owned or rented by a livestock producer or manager, for the purpose of land management, and for which the owner or land manager receiving grazing services pays compensation to the service provider. This research project seeks to gather detailed information about producers in the Western United States, providing grazing services under this project’s definition of “service-grazing”, with a focus on those operating in California, in order to discover the business models or practices necessary to be successful within a service-based grazing operation. To this end, an online survey consisting of 59 questions was designed and administered to 25 service-grazers operating with the Western United States. Demographic data collected suggested that service-grazers tend to be younger than most sheep producers. They are also highly educated and generally not generational farmers. The majority of service grazers graze mostly goats and are highly dependent on off-farm income. Due to the limited number of responses received to the survey, it is recommended that future work be split into two parts: 1) compiling an accurate and up-to-date list of producers providing grazing services, with detailed demographic information and specific characteristics of each operation; 2) a further survey to question those producers as to the feasibility of transitioning, in whole or in part, from a production-based livestock operation to one providing grazing services.

Page generated in 0.0343 seconds