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Investigation of the Toxicity and Toxicokinetics of Selenium from the Accumulator Plant Symphyotrichum spathulatum (Western Mountain Aster) in SheepWilhelm, Amanda 01 May 2010 (has links)
This study was designed to observe the effects of selenium from plant material in sheep after a single, oral dose. Purified sodium selenite and selenomethionine were given as positive controls. The plant Symphyotrichum spathulatum (Western Mountain Aster) was collected, analyzed for selenium content, and administered orally to sheep at varying doses according to body weight. Clinical signs were observed for 7 days during which time whole blood, serum, and expired air were collected. Following euthanasia, tissues were collected for histopathological analysis and mineral analysis. Clinical signs were less apparent than expected and included depression and mild dyspnea in sheep receiving the highest doses of selenium as plant material, whereas pathologic lesions were prominent. Acute myocardial degeneration and necrosis was most severe in the highest dose animals, but present to lesser degrees as dose decreased. Pulmonary lesions of edema and congestion were less frequently observed. Thirteen animals died prior to study completion. Selenium concentration in tissues, brain, liver, kidney cortex, atrium, ventricle, and skeletal muscle, increased with increasing dose of plant material. Treatment had a significant impact on selenium concentration in all tissues collected for mineral analysis (P < 0.01). Whole blood and serum were collected to study the toxicokinetics of selenium in these sheep. Serum kinetic parameters that increased significantly with increasing dose included the elimination rate constant, peak selenium concentration, and area under the selenium concentration versus time curve. Serum kinetic parameters that significantly decreased with increasing dose included the absorption and elimination half-lives. Whole blood kinetic parameters that increased significantly with increasing dose included the elimination rate constant, peak selenium concentration, and area under the curve. Expired air was collected to study the respiratory toxicokinetics of selenium in the sheep. The selenium concentration in expired air from sheep receiving selenomethionine was significantly greater than all other treatments (P < 0.0001) at all collection time points. But an intriguing finding was the dramatic differences in elimination profile curves as selenium dose increased with the plant material. The highest dose group elimination curve continually increased through all collection time points. All other groups dosed with plant material saw a decrease in selenium elimination by the last collection time point.
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Habitat Selection by Large Wild Ungulates and Some Aspects of the Energy Flow in a Sub-tropical African Savanna Woodland EcosystemHirst, Stanley M. 01 May 1973 (has links)
A study of habitat selection by large wild ungulates was carried out on a 50 cm2 area in the sub-tropical Lowveld region of eastern Transvaal province, South Africa. Estimations were made of herbaceous forage net productivity and ungulate secondary productivity on the same area.
Fourteen vegetation types, varying in composition and structure from open savanna to dense woodland, were delineated by association analysis. Structural and vegetational characteristics which were considered to influence ungulate distribution were measured within each vegetation type.
The study area supported resident populations of seven ungulate species during the wet season; drv season densities were higher due to population influxes from surrounding areas. Densities ranged from 13 to 67 animals per km2, with impala making up from 40 to 70 percent of the total population, wildebeest 10 to 40 percent, and lesser proportions of giraffe, zebra, kudu, warthog and waterbuck. Savanna vegetation types supported total densities of up to 185 animals/km2, while wooded types support fewer animals.
Waterbuck were the most selective of the ungulates and concentrated mainly in the riparian woodland. Wildebeest, zebra and giraffe made variable use of savanna and open woodland types. Warthog preferred savanna types and avoided woodland. Impala were less selective, and kudu showed no habitat preferences. Ungulate distribution was related to several habitat characteristics, and the key factors were found to differ in each case. Each species had a unique combination of habitat characteristics to which it responded in linear fashion, and this was considered to be the way in which ungulates avoided competition by achieving spatial separation.
Herbaceous forage standing crops and net production were functions of vegetation composition, soil types, rainfall and extent of ungulate utilization. Standing crops ranged from 350 to 4104 kgs/ha air-dried forage. Net primary production ranged from zero to 2719 kgs/ha; vegetation types on sandy soils did not produce in years with poor precipitation. Ungulates consumed about one-fourth of the herbaceous net primary production during the wet season and more than four-fifths during the course of a full year.
Ungulate biomass on the area averaged about 40 kg/ha during the wet season and 65 kg/ha in the dry season, but biomasses varied a great deal with vegetation type, ungulate population species coMposition and seasonal densities. Ungulate secondary product ion varied correspondingly and ranged from 1.3 x 10-3 kcal/m2 per day to 4.8 x 10-3 kcals/m2 per day. Overall secondary production rate for the 2-year study period was 0.97 kcals/m2 per year, produced from a mean standing crop of 7.46 kcal/m2.
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Assessing Vehicle-Related Mortality of Mule Deer in UtahOlson, Daniel D. 01 May 2013 (has links)
Roads are essential in modern societies, but as populations grow and traffic volumes rise, roads will continue to be built and expanded. As a result, the effects that roads have on wildlife will likely intensify, making it imperative that managers understand those effects so mitigation can be directed accordingly. In Utah, considerable areas of mule deer (Odocoileus hemionus) habitat have been bisected by roads. Mule deer are commonly involved in vehicle collisions and there is concern that roads and vehicle traffic are impacting populations. This project was conducted to determine the number and demographic effects of deer-vehicle collisions, to examine how movements and survival of deer were impacted by roads, and to develop a smartphone-based reporting system for wildlife-vehicle collisions. Accurate estimates of DVCs are needed to effectively mitigate the effects of roads, but great uncertainty exists with most deer-vehicle collision estimates. I estimated the number of deer-vehicle collisions using carcass surveys, while accounting for several sources of bias to improve accuracy. I estimated that 2-5 % of the statewide deer population was killed in vehicle collisions annually. The effect that vehicle collisions have on deer abundance depended not only on the number of deer killed but also on the demographic groups removed. I found that 65 % of deer killed in vehicle collisions were female and 40 % were adult females. As female deer are the primary drivers of population growth, my data suggest vehicle collisions could significantly affect population abundance. However I was unable to detect a decreasing trend in deer abundance. Deer have distinct movement patterns that affect their distribution in relationship to roads. I analyzed deer movements during two consecutive winters (2010-11 & 2011-12) to determine what effect climate had on deer movements and vehicle collision rates. I observed that as snow depth decreased, the distance that deer occurred from roads increased. As a result road crossing rates declined, as did the number of vehicle collisions. This suggests a causal mechanism by which winter conditions influence vehicle collision rates. Currently there is a need for an efficient wildlife-vehicle collision data collection. I envisioned and, working with colleagues, helped develop a smartphone-based system for reporting wildlife-vehicle collision data. The WVC Reporter system consisted of a mobile web application for data collection, a database for centralized storage of data, and a desktop application for viewing data. The system greatly improved accuracy and increased efficiency of data collection efforts, which will likely result in improved mitigation and ultimately increased safety for motorists and deer.
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Factors Affecting the California Quail Populations in Uintah County, UtahNielson, R. Lynn 01 May 1952 (has links)
The California Quail is native to the coastal and semi-arid regions of California extending north into Oregon. Two subspecies are commonly recognized. the California Quail (Lophortyx californica brunnescens Ridgway), and the Valley Quail (Lophortyx californica californica Shaw) 0 The two forms are very similar in coloration and habits and, for the purpose of this study, no effort is made to distinguish the two.
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A Management Study of the Idaho-Utah Interstate Deer Herd With Special Reference to the Sublett, Black Pine, and East Raft River Mountain UnitDiem, Kenneth L. 01 May 1952 (has links)
Extensive deer migrations have been observed for many, years in western mountain regions. More recently several complex interstate migrations have become the objects of careful study and the subjects of special wildlife movement programs. The interstate deer migrations between the Sublett-Black Pine, Idaho, areas and the East Raft River Mountain, Utah, area are not exceptional. These migrations are now of such a magnitude that they are creating management problems of increasing importance to the 2 states involved.
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Performance & Carcass Traits of Swine of Four Different Phenotypes & Three USDA GradesAlthaus, Jon 01 December 1988 (has links)
The purpose of this study was to compare the performance and carcass characteristics of swine of four different phenotypes and three USDA grades.
Hogs were placed into phenotypic groups of 24 each and penned by group. These pens were ideal, cutability, light muscled, fat, VS US and US The hops were fed a 16% corn and soybean meal ration fortified with appropriate minerals and vitamins. They were housed in a total confinement curtain-sided Kentucky plan building with a partially slatted floor. The hogs were weighed at 6-week intervals throughout the project to monitor average daily gain and pen feed efficiency. Twelve hogs from each pen were slaughtered at approximately 2(0 pounds and the remaining twelve pigs at approximately 230 pounds to determine if differences in performance and carcass characteristics remained consistent or became greater at heavier weights. Carcass weight, backfat at the tenth rib and last rib, length and loin eye area were obtained on each carcass. Data were adjusted to the group means for the heavy and light groups using least squares analysis. The mean for the heavy group was 255 pounds and the mean for light group was 229 pounds.
Results of the study showed the ideal pen to have significantly higher (P<.01) average daily gain than all other pens at 229 pounds and significantly higher (P<.01) average daily gain than the cutability, US #2, and US #3 pens at 255 pounds. The two leanest and heaviest muscled pens were cutability and US #1. These two pens had significantly (P<.01) lower fat and larger loin eye area than the light muscled. US #3 and fat pens at 229 pounds. The fat pen had significantly (P.-01) greater backfat, smaller loin eye area, and lower percent muscle than all other pens in the heavy group. The cutability and US #1 pens had significantly higher (P<.01) percent muscle than the light muscled, US #3, and fat pens. The ideal, US #1, and cutability pens had significantly (P<.01) higher lean gain per day on test than all other pens with the exception of the light muscled pen taken to the heavier slaughter weight.
The ideal, cutabilitv, and US #1 hogs had the lowest average values for feed per unit of lean gain. The fat pen required 2.5 pounds more feed to produce a pound of loan gain than ideal. cutability or US #1 pens. The US #1 group required 1.50 fewer pounds of feed per pound of lean growth than US #2 and #3 groups.
These results indicate that the ideal pen was superior in terms of performance and lean growth. The cutabilitv and US #1 pen were the leanest and heaviest muscled. The fat group was extremely high in backfat, low in loin eye area and the most inefficient in converting feed into lean tissue.
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THE IMPACT OF INSULIN DYSREGULATION ON PROTEIN METABOLISM IN HORSESLoos, Caroline Margot Marcelle 01 January 2018 (has links)
Insulin plays a vital role in whole-body metabolism and provides a major anabolic stimulus for cellular signaling pathways, including those involved in the metabolism of glucose and protein. Consequently, insulin dysregulation (ID) is known to alter molecular signal transduction in insulin-sensitive tissues such as skeletal muscle, thereby disrupting glucose metabolism and compromising protein synthetic capacity. Our first objective was to induce ID in healthy horses by administering dexamethasone (DEX), a potent glucocorticoid, for 21 days. We evaluated the effects on insulin-stimulated muscle protein signaling components involved in the mammalian target of rapamycin (mTOR) pathway. DEX-induced ID reduced insulin-stimulated activation of downstream (rpS6, 4EBP-1) mTOR signaling and increased atrogin-1 abundance, a marker for protein breakdown (P < 0.05). Additionally, 21 days of DEX elevated plasma amino acids levels in insulin-stimulated conditions, indicative of reduced uptake or increase release into circulation (P < 0.05). The second objective was to evaluate the short-term effects of DEX treatment in healthy horses. Plasma insulin, glucose and amino acid dynamics and activation of mTOR signaling pathways following an oral sugar test (OST) or intake of a high protein meal were evaluated before and after 7 days of DEX treatment, and after 7 days of no treatment. Seven days of DEX treatment increased basal levels of glucose, insulin and several amino acids (P < 0.05). Additionally horses treated with DEX had an exacerbated insulin response to the OST and consumption of the high protein meal in comparison to control horses (P < 0.05). The majority of blood metabolites returned to basal levels after 7 days of recovery from DEX treatment, indicating these effects were transient. Short-term DEX treatment decreased overall activation of mTOR and FoxO3 but increased total FoxO3 and IRS-1 abundance (P < 0.05). Postprandial activation of rpS6 was greater in horses treated with DEX for 7 days but was lower in those horses after 7 days of recovery from treatment (P < 0.05). Postprandial activation of ULK and AMPK tended to be greater in DEX treated horses (P < 0.1). Akt phosphorylation and mysotatin abundance were lower after the OST in DEX treated horses (P < 0.05). The final objective was to evaluate whether similar changes in postprandial metabolic responses would be seen in horses with naturally occurring ID. Plasma insulin, glucose and amino acid responses following ingestion of a high protein meal were determined in mature horses with equine metabolic syndrome (EMS). Horses with EMS had higher basal plasma insulin concentrations but lower levels of aspartate, glutamate, asparagine and plasma urea nitrogen in comparison to healthy controls (P < 0.05). Consumption of a high protein meal resulted in a 9-fold greater insulin response and higher postprandial levels of various amino acids (P < 0.05). Together this research indicates that ID affects whole body protein metabolism by altering cellular signaling pathways in healthy and diseased horses.
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LONG-TERM EFFECTS OF DIETARY COPPER SOURCE AND LEVEL ON PERFORMANCE AND HEALTH OF SOWS AND PIGLETSLu, Ning 01 January 2018 (has links)
The objectives of this study were to investigate the long-term effects of feeding increasing supplemental levels (20, 120, or 220 mg/kg) of dietary copper (Cu) as tribasic copper chloride (TBCC) or copper sulfate (CuSO4) on performance, antioxidant status, nutrient digestibility, and trace mineral deposition of sows and piglets; as well as to assess nursery dietary Cu levels on growth performance and response to immunological challenge in nursery pigs from sows fed either high or low Cu diets. In the long-term sow experiment, sows fed TBCC diets had greater adjusted weaning weight for litter and piglet (P < 0.10), as well as adjusted litter and piglet weight gain (P < 0.10) when compared to sows that received CuSO4 diets. Increasing dietary Cu level linearly increased live born piglet weight (P = 0.06). Sows fed TBCC diets had lower apparent total tract digestibility (ATTD) of ether extract (P = 0.01) during late gestation, but greater ATTD of dry matter, nitrogen, and phosphorous during lactation (P < 0.05). Increasing Cu levels linearly increased dry matter digestibility in lactating sows (P = 0.02). Milk from sows fed TBCC diets had a greater concentration of protein (P = 0.02) than that from sows fed CuSO4 diets. Increasing Cu levels increased levels of milk fat and Cu (linear, P < 0.05); but linearly decreased lactose and Zn levels (P < 0.05). Lactating sows fed TBCC diets had a greater activity of Cu/Zn superoxide dismutase (SOD) and ceruloplasmin in serum than those fed CuSO4 diets (P < 0.05). Increasing dietary Cu levels increased total and Cu/Zn SOD activity for lactating sows (linear, P < 0.05). Sows fed TBCC diets had lower concentrations of Cu (P = 0.04), but higher concentrations of iron and manganese (P < 0.05) in the liver, when compared to those fed with CuSO4 diets. In addition, liver Cu concentrations increased with increasing dietary Cu levels (linear and quadratic, P < 0.05). Increasing dietary Cu levels resulted in the elevation of concentrations and contents of Cu in the liver of weanling piglets (linear, P < 0.0001). In the nursery pig experiment, pigs from sows fed 120 mg/kg Cu diets had greater ADG from d 0 to 14 (P < 0.05), and tended to have greater ADG in the overall period (P < 0.08), when compared to pigs from sows fed 20 mg/kg Cu diets. During the lipopolysaccharide challenge period, the challenged pigs from sows fed 120 mg/kg Cu had a greater overall rectal temperature than those from sows fed 20 mg/kg Cu (P = 0.01). Also, the challenged pigs fed with 220 mg/kg Cu diets had greater serum tumor necrosis factor-alpha concentration over time as compared to those fed 20 mg/kg Cu diets (P = 0.03). In summary, the TBCC may be a superior Cu source compared to CuSO4 regarding reproductive performance, and higher dietary Cu levels result in greater birth weight of piglets; furthermore, high Cu levels in sow and nursery diets promote growth performance of nursery pigs and affects their responses to immunological challenge.
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RESPONSES OF BOVINE PITUITARY TRANSCRIPTOME PROFILES TO CONSUMPTION OF TOXIC TALL FESCUE AND FORMS OF SELENIUM IN VITAMIN-MINERAL MIXESLi, Qing 01 January 2019 (has links)
The first goal of the current research was to determine whether gene expression profiles differed between whole pituitaries of growing beef steers grazing pastures containing high (HE) or low (LE) amounts of toxic endophyte-infected tall fescue. The global (microarray analysis) and selected targeted (RT-PCR) mRNA expression patterns of pituitaries collected from beef steers (BW = 266 ± 15.5 kg) that had been randomly assigned to undergo summer-long grazing (89 to 105 d) of either HE (0.52 ppm ergot alkaloids) or LE (< 0.03 ppm ergot alkaloids) pastures were compared. Gene expression data were subjected to one-way ANOVA. The pituitaries of HE steers had 542 differentially expressed genes, and the pattern of altered gene expression was dependent on treatment. Targeted RT-PCR analysis corroborated these findings, including decreased expression of DRD2, PRL, POU1F1, GAL, and VIP and that of POMC and PCSK1, respectively. Canonical pathway analysis (Integrated Pathway Analysis, IPA) identified HE-dependent alteration in signaling of additional pituitary-derived hormones, including growth hormone and GnRH. In conclusion, consumption of endophyte-infected tall fescue alters the pituitary transcriptome profiles of steers in a manner consistent with their negatively affected physiological parameters. The second goal of this project was to test the hypothesis that sodium selenite (ISe), SEL-PLEX (OSe), vs. a 1:1 blend (MIX) of ISe and OSe in a basal vitamin-mineral (VM) mix would differentially alter pituitary transcriptome profiles in growing beef steers (BW = 183 ± 34 kg) commonly grazing an endophyte-infected tall fescue (HE) pasture. Steers were randomly selected from herds of fall-calving cows grazing HE pasture and consuming VM mixes that contained 35 ppm Se as either ISe, OSe, or MIX forms. Steers were weaned, depleted of Se for 98 d, and subjected to summer-long common grazing of a 10.1 ha HE pasture containing 0.51 ppm ergot alkaloids. Steers were assigned (n = 8) to the same Se-form treatments on which they were raised. Selenium treatments were administered by daily top-dressing 85 g of VM mix onto 0.23 kg soyhulls, using in-pasture Calan gates. Pituitaries were collected at slaughter and changes in global (microarray) and selected (RT-PCR) mRNA expression patterns determined. The effects of Se treatment on relative gene expression were subjected to one-way ANOVA. The form of Se affected the expression of 542 annotated genes. Integrated Pathway Analysis found a canonical pathway network between prolactin and POMC/ACTH/ α-MSH synthesis-related proteins, and that mitochondrial dysfunction was a top-affected canonical pathway. Targeted RT-PCR analysis found that the relative abundance of mRNA encoding prolactin and POMC/ACTH/ α-MSH synthesis-related proteins was affected by the form of Se, as were mitochondrial dysfunction-related proteins OSe steers appeared to have a greater prolactin synthesis capacity vs. ISe steers through decreased dopamine receptor D2 signaling, whereas MIX steers had a greater prolactin synthesis capacity and release potential by increasing TRH concentrations than ISe steers. OSe steers also had a greater ACTH and α-MSH synthesis potential than ISe steers. We conclude that form of Se in VM mixes affected genes responsible for prolactin and POMC/ACTH/α-MSH synthesis, and mitochondrial function in pituitaries of growing beef steers commonly grazing an HE pasture. The third goal was to test the hypothesis that sodium selenite (ISe), SEL-PLEX (OSe), vs. a 1:1 blend (MIX) of ISe and OSe in a basal vitamin-mineral (VM) mix would differentially alter selenoprotein profiles in pituitaries and livers of growing beef steers commonly grazing an endophyte-infected tall fescue (HE) pasture (i.e., the same steers used in Goal 2). The effects of Se treatment on relative gene expression were subjected to one-way ANOVA. The mRNA content of 6 selenoproteins in the pituitary was affected by Se treatments, along with two selenoprotein P receptors, whereas the expression of two selenoproteins was altered in the liver. We conclude that the change in selenoprotein gene expression in pituitaries indicates that OSe steers have a greater potential capacity to manage against oxidative damage, maintain cellular redox balance, and have a better quality control of protein-folding in their pituitaries than ISe steers. The change in selenoprotein gene expression by the liver indicates that MIX steers have a greater redox signaling capacity and capacity to manage oxidative damage than ISe steers.
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BEHAVIORAL AND PHYSIOLOGICAL ADAPTATIONS ASSOCIATED WITH FEED INTAKE DURING TRANSITIONING CATTLE TO HIGH-GRAIN DIETSMcLean, Amanda M. 01 January 2019 (has links)
Transitioning cattle from a high-forage to a high-concentrate diet increases the risk for ruminal acidosis and is often related to decreased feed intake, which compromises animal health and performance. Since control of feed intake and rumen motility are closely related, we hypothesized that a reduction in rumen motility may be associated with a reduction in feed intake during this transition. Computer programs were created to analyze feed disappearance and rumen pressure data for feeding behavior as well as identification and characterization of rumen contractions, respectively. This method enabled timely analysis of large datasets and removed subjectivity associated with manual analysis. In the second part of this series, cattle were moderately transitioned from a 70% to a 90% concentrate diet, and SARA was induced. Although, reductions in feed intake were modest, on day 2 of high-grain feeding, animals slowed feed consumption rate and displayed a reduction in rumen contraction frequency, amplitude, and duration. Next, an abrupt transition from 50% to 90% concentrate was used to induce ruminal acidosis and cause some animals to stop eating. The abrupt increase in dietary concentrate was also associated with reductions in rumen motility. Patterns of ruminal pH, viscosity, and motility changes were related to when cattle reduced feed intake. Endotoxin quantification in blood samples from the ruminal vein, portal vein, and mesenteric artery suggested the point of endotoxin translocation into blood was across the ruminal epithelium. Additionally, the greater the concentration of endotoxin in the plasma, the more likely animals were to go “off-feed.” By understanding the physiological and behavioral mechanisms by which cattle adapt to high-grain diets, we can improve animal health and performance through these diet transitions.
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