Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item On-Farm Dry Matter Analysis to Improve Feed Delivery Precision on Dairy Farms(2011) French, Karin R.; Kohn, Richard A; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Uncertainty in dairy ration content impacts feed efficiency, milk production, expenses, and environmental losses. When measuring silage by weight, unknown changes in dry matter (DM) may change the total mixed ration. The objective of this study was to measure variation in silage DM on selected farms and evaluate an electronic method of on-farm DM analysis. Of 31 Maryland farms surveyed, 63% reported DM analysis by an on-farm method, 83% by any method including laboratory measurement. Eight producers performed DM analysis daily for 21 days using a Farmex 1210 Electronic Silage Tester (on-farm) and they recorded precipitation; matching samples were analyzed for DM in a laboratory after oven drying ("standard" method, 55°C followed by 100°C) and by using a Farmex 1210 (laboratory). The standard deviation of mean silage DM varied from 0.72% to 3.33% DM, depending on farm. The electronic method compared poorly to standard DM analysis for most farms.Item INTEGRATED PEST MANAGEMENT OF FUSARIUM HEAD BLIGHT IN SOFT RED WINTER WHEAT(2011) Reed, Elizabeth; Grybauskas, Arvydas; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Fusarium head blight (FHB), caused by Fusarium graminearum, is a destructive disease of the soft red winter wheat grown in the Mid-Atlantic region. Management of FHB focuses primarily on foliar fungicides or cultivar resistance. The purpose of this research was to examine how type II resistance (resistance to spread of the pathogen) is affected by multiple infections along the spike. The combination of type II resistance and fungicide as a way to manage FHB was evaluated in both the greenhouse and field settings. Finally, the role of increased foliage density in an integrated pest management program that included fungicide and cultivar resistance was also evaluated. Multiple infections occurring along a single wheat spike can overwhelm the type II resistance present in some cultivars. The combination of type II resistance and fungicide was the best management practice for FHB than either alone. Foliage density did not improve FHB disease ratings.Item Scab Resistance QTLs are Associated with Quality and Agronomic Traits of Soft Red Winter Wheat(2011) Cardwell, Lydia Ann; Costa, Jose; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Fusarium head blight (FHB) is a devastating fungal disease affecting Triticum aestivum crops worldwide. While many quantitative trait loci (QTL) responsible for FHB resistance have been reported, some widely used sources are from exotic cultivars that may carry undesirable alleles linked with resistance. Ning_7840, a Chinese hard red spring wheat, contains a major FHB QTL on the 3BS chromosome, along with two minor QTL on the 5A and 2DL chromosomes. Ning_7840 was crossed with Pioneer_2643, a soft red winter wheat, to create 86 recombinant inbred lines. The effect of the Ning_7840 alleles on agronomic traits and milling and baking quality traits was examined over three growing seasons in Maryland. While the 3BS QTL was not associated negatively with other traits, the 2DL and 5A QTL were. This suggests the introduction of FHB resistance QTL on 5A and 2DL into soft red winter wheat may negatively affect agronomic and quality traits.Item Urban Kibbutz: Integrating Vertical Farming and Collective Living in Jerusalem, Israel.(2010) Ankri, Daniel Scott; Ankri, Daniel S; Architecture; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This thesis is predicated around the critical question: how do we feed an exponentially growing world population? With 80% of the world population living in an urban context by the year 2050, it is crucial for us to explore the architectural potential of what city living can be like in combination with urban farming. Using the social typology of a kibbutz as a vehicle for investigation, this thesis analyzes the Israeli version of agricultural co-housing. Parallel to this analysis is a study on the technique of urban agriculture which can be applied to the site in the horizontal and vertical dimensions. The site, located in the cultural center of Jerusalem, Israel, is an underdeveloped parking lot adjacent to the famous shuk (farmers market), home to hundreds of vendors competitively selling their produce. This thesis begins by researching and analyzing two different themes. The first theme focuses on various hydroponic techniques which would consist of a comprehensive study of the eco-design components of urban farming and its applications. The second theme will investigate the social characteristics of a kibbutz and how we can apply this collective community into an urban environment. The end result will be a synthesis of the two that will allow us to explore the potential of integrating collective living with urban agriculture. What would the product be like when people begin to take responsibility for the growing of their own food? Or when the separation between architecture and agriculture blends into a single entity?Item Genetic Variation in Nitrogen and Phosphorus Levels in Broiler Excreta: Opportunity for Improving both Birds and the Environment(2010) sasikala appukuttan, arun kirshna; Siewerdt, Frank; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The increase in poultry meat consumption has resulted in intensified poultry farming operations with consequent concentration of excreta in major production areas. The nutrient content in the soil surrounding the poultry farms has increased as a result of the high content of nitrogen (N) and phosphorus (P) in the poultry excreta. The current study aimed to propose a strategy to reduce the N and P content in excreta through genetic selection of broilers for efficient nutrient utilization. The traits measured (on a dry matter basis) were the percentage of N in the excreta (PNE) and the percentage of P in the excreta (PPE). Individual 24-hr excreta samples were collected from 6 wk old birds. Excreta samples were collected from a commercial breeding farm at two different time periods from line A and line B birds respectively, and analyzed for PNE and PPE. Analysis of excreta samples collected during the first period (197 bird samples belonging to 15 sire families) and second period (278 birds belonging to 25 sire families) suggested a heritability of 0.08, 0.16 for PNE and 0, 0.20 for PPE, respectively. Phenotypic and genetic correlations between the measured traits from the two lines were very low; however, phenotypic correlation analysis of PNE and PPE with other traits of commercial interest showed some favorable as well as neutral associations. Blood samples collected from the birds were used for an association study of the excreta traits with four candidate genes. The candidate genes were selected based on the results of previous research. Some of the SNPs from the candidate genes were found to have additive and dominance effect on the excreta and production traits and were usually favorably associated with mutations in higher frequency in the populations. The results suggest that genetic selection of birds for PNE and PPE could improve the environment and the market value of the birds.Item Proteomic Profiling and Label-Free Quantification of Bovine Milk Proteins during Experimentally Induced Escherichia coli Mastitis(2009) Boehmer, Jamie Layne; Peters, Robert R; Bannerman, Douglas D; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Coliform mastitis has been a primary focus of dairy cattle disease research due to staggering affiliated losses, severe systemic complications arising from host inflammatory response to lipopolysaccharide, and the poor response of coliform pathogens to antimicrobials. Reliable biomarkers are needed to evaluate the efficacy of adjunctive therapies for the treatment of inflammation associated with coliform mastitis, and to aid in the approval of new veterinary drugs. The aims of the current analyses were to utilize proteomic methodologies to evaluate protein expression in whey from cows with experimentally induced coliform mastitis, and to employ label-free quantification strategies to estimate changes in relative abundance of proteins identified in milk over the course of clinical infection. Two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI- TOF) mass spectrometry (MS) resulted in the identification of complement factors, antimicrobial proteins, and acute phase proteins in mastitic milk. Analysis using liquid chromatography (LC) inline with electrospray ionization - quadrupole TOF tandem mass spectrometry (MS/MS) resulted primarily in the identification of abundant whey and casein proteins, and the transient detection of proteins related to host response. Nano-LC- nanospray-MS/MS using a linear ion trap, however, led to the robust discovery of over fifty inflammatory proteins in whey from mastitic milk, including the novel markers kininogen-2 and inter-alpha trypsin inhibitor heavy chain-4. Normalized spectral counts were compared to enzyme-linked immunosorbant assay (ELISA) for select proteins to assess the accuracy of the spectral count data. Similar expression patterns were detected using spectral counts and ELISA. Results indicate that proteomic methodologies can detect biomarkers of coliform mastitis in bovine milk during clinical infections, and that spectral counts are a viable means of evaluating relative changes in protein biomarkers of mastitis, including those for which no antibody currently exists.Item Forage Radish Cover Crop Effects on Mycorrhizal Colonization and Soil Test Phosphorus(2009) White, Charles Macaulay; Weil, Ray R; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Forage radish (Raphanus sativus L. var. longipinnatus) and cereal rye (Secale cereale L.) cover crops were examined for their effects on arbuscular mycorrhizal colonization and P acquisition of a subsequent corn (Zea mays L.) silage crop. Soil test P following these cover crops was also measured in bulk soil collected at three depths in the surface soil and in soil sampled within 3 cm of forage radish tap root holes. Forage radish never decreased mycorrhizal colonization and rye sometimes increased colonization of the subsequent crop compared to growing no cover crop. The extent of colonization of corn roots by arbuscular mycorrhizal fungi was positively correlated with corn shoot tissue P concentrations. Slight vertical soil test P stratification in the bulk soil occurred following both forage radish and rye cover crops at some sites. A large increase in soil test P occurred within 3 cm of forage radish tap root holes.Item Effects of barrier perches and stocking density on the behavior, space use, and leg health of the domestic fowl (Gallus gallus domesticus)(2009) Ventura, Beth Ann; Estevez, Inmaculada; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The objective of this study was to discern whether providing enrichment in the form of barrier perches across a range of densities might improve leg and foot health and promote behavioral expression and more even use of space in broilers. To investigate this, 2,088 day-old broiler chicks were randomly assigned to one of three barrier treatments at one of three densities. Effects on behavior, space use, foot and hock health, tibia fluctuating asymmetry, fear and production were subsequently assessed. Higher densities appeared to compromise broiler welfare, seen by increased tibia length asymmetry, poorer foot and hock health, suppression of activity, increased disturbances, and decreased use of space. Conversely, barrier perches - particularly simple barriers - appeared to improve footpad quality, promote increased perching and activity, decrease aggression and disturbances, and improve use of the central pen space, all without negatively impacting production traits.Item SEASONAL AND INTERANNUAL VARIABILITY OF EMISSIONS FROM CROP RESIDUE BURNING IN THE CONTIGUOUS UNITED STATES(2009) McCarty, Jessica; Justice, Chrisopher O; Geography; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Crop residue burning is a global agricultural practice used to remove excess residues before or after harvest. Crop residue burning in the contiguous United States (CONUS) has been documented at the regional and state-level by governmental organizations and in the scientific literature. Emissions from crop residue burning in the CONUS have been found to impair local and regional air quality, leading to serious health impacts and legal disputes. Currently, there is no baseline estimate for the area and emissions of crop residue burning in the CONUS. A bottom-up model for emissions calculations is employed to calculate CO2, CO, CH4, NO2, SO2, PM2.5, PM10, and Pb emissions from crop residue burning in the CONUS for the years 2003 through 2007. These atmospheric species have negative impacts on air quality and human health and are important to the carbon cycle. Spatially and temporally explicit cropland burned area and crop type products for the CONUS, necessary for emissions calculations, are developed using remote sensing approaches. The majority of crop residue burning and emissions in the CONUS are shown to occur during the spring (April - June) and fall harvests (October - December). On average, 1,239,000 ha of croplands burn annually in the CONUS with an average interannual variability of ± 91,200 ha. In general, CONUS crop residue burning emissions vary less than ±10% interannually. The states of Arkansas, California, Florida, Idaho, Texas, and Washington emit 50% of PM10, 51% of CO2, 52% of CO, and 63% of PM2.5 from all crop residue burning in the CONUS. Florida alone emits 17% of all annual CO2, CO, and PM2.5 emissions and 12% of annual PM10 emissions from crop residue burning. Crop residue burning emissions in the CONUS account for as little as 1% of global agricultural emissions and as much as 15% of all agricultural burning emissions estimates in North America, including Mexico and Canada. The results have implications for international, federal, and state-level reporting and monitoring of air quality and greenhouse gas and carbon emissions aimed at protecting human health, mitigating climate change, and understanding the carbon cycle.Item Yielding Architecture: A Manifesto for [Urban + Agri]Culture(2008) Dickson, Beret; Williams, Isaac S; Architecture; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The contemporary, monoculture-based agricultural model is failing, as evidenced by worldwide food shortages, environmental degradation, and mono-diets. Grassroots efforts to reanimate neglected urban space with food production foretell an impending farming revolution. Additionally, 20th century economic changes have left many American cities devoid of the industry around which they were founded, leaving behind vast swaths of uninhabited and often polluted sites. This thesis imagines reclaiming these post-industrial landscapes with institutional infrastructures constructed to support the burgeoning urban agriculture revolution. Recasting what and how urban farming can yield will provide a new vision for both architecture and agriculture. A conceptual agenda that reinterprets yield as both value and potential suggests a high-performance architecture that exhibits the efficiency and sustainability found in natural systems. It also demands an evolutionary architecture that establishes a framework for potential forms, events, and output by yielding to external circumstances and inevitable future change.
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