Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Theses/Dissertations

University of Kentucky

Discipline
Keyword
Publication Year
Publication

Articles 1 - 30 of 928

Full-Text Articles in Life Sciences

Strain-Specific Protein Interaction And Localization Of Two Strains Of Potato Yellow Dwarf Virus And Functional Domains Of Their Matrix Protein, Chanyong Jang Jan 2019

Strain-Specific Protein Interaction And Localization Of Two Strains Of Potato Yellow Dwarf Virus And Functional Domains Of Their Matrix Protein, Chanyong Jang

Theses and Dissertations--Plant Pathology

Potato yellow dwarf virus (PYDV) is the type species of the genus nucleorhabdovirus which is typified by its nucleotropic characters of the members. The virus accomplishes its replication and morphogenesis in the nuclei of infected cells. Two strains, Constricta strain (CYDV) and Sanguinolenta strain (SYDV) have been described at the level of vector-specificity. CYDV is vectored by Agallia constricta and SYDV is transmitted by Aceratagllia sanguinolenta. The full-length genome of CYDV was sequenced. The 12,792 nt antisense genome encodes seven open reading frames in the order of, nucleocapsid protein (N), unknown protein (X), phosphoprotein (P), movement protein (Y), matrix ...


Host Restriction Factors In The Replication Of Tombusviruses: From Rna Helicases To Nucleocytoplasmic Shuttling, Cheng-Yu Wu Jan 2019

Host Restriction Factors In The Replication Of Tombusviruses: From Rna Helicases To Nucleocytoplasmic Shuttling, Cheng-Yu Wu

Theses and Dissertations--Plant Pathology

Positive-stranded (+)RNA viruses replicate inside cells and depend on many cellular factors to complete their infection cycle. In the meanwhile, (+)RNA viruses face the host innate immunity, such as cell-intrinsic restriction factors that could block virus replication.

Firstly, I have established that the plant DDX17-like RH30 DEAD-box helicase conducts strong inhibitory function on tombusvirus replication when expressed in plants and yeast surrogate host. This study demonstrates that RH30 blocks the assembly of viral replicase complex, the activation of RNA-dependent RNA polymerase function of p92pol and viral RNA template recruitment.

In addition, the features rendering the abundant plant DEAD-box helicases either ...


Targeting Maladaptive Plasticity After Spinal Cord Injury To Prevent The Development Of Autonomic Dysreflexia, Khalid C. Eldahan Jan 2019

Targeting Maladaptive Plasticity After Spinal Cord Injury To Prevent The Development Of Autonomic Dysreflexia, Khalid C. Eldahan

Theses and Dissertations--Physiology

Vital autonomic and cardiovascular functions are susceptible to dysfunction after spinal cord injury (SCI), with cardiovascular dysregulation contributing to morbidity and mortality in the SCI population. Autonomic dysreflexia (AD) is a condition that develops after injury to the sixth thoracic spinal segment or higher and is characterized by potentially dangerous and volatile surges in arterial pressure often accompanied with irregular heart rate, headache, sweating, flushing of the skin, and nasal congestion. These symptoms occur in response to abnormal outflow of sympathetic activity from the decentralized spinal cord typically triggered by noxious, yet unperceived nociceptive stimulation beneath the level of lesion ...


Anthelmintic Resistance In Equine Parasites: Mechanisms And Treatment Approaches, Jessica Scare Kenealy Jan 2019

Anthelmintic Resistance In Equine Parasites: Mechanisms And Treatment Approaches, Jessica Scare Kenealy

Theses and Dissertations--Veterinary Science

Anthelmintic resistance of parasites infecting livestock animals is a global problem resulting in decreased animal welfare and production losses. Horses are not exempt from this issue as wide-spread anthelmintic resistance exists among the equine cyathostomins and Parascaris spp. Of the three drug classes available for treating equine intestinal helminths anthelmintic resistance, defined as less than 90-95% drug efficacy, exist to all three. New pharmaceutical control regimens and the elucidation of parasite drug response mechanisms are needed.

Two studies were carried out evaluating combination deworming regimens. A population of cyathostomins with known resistance to the benzimidazole (BZ) and pyrimidine drug classes ...


Mechanisms Of Type-I Ifn Inhibition: Equine Herpesvirus-1 Escape From The Antiviral Effect Of Type-1 Interferon Response In Host Cell, Fatai S. Oladunni Jan 2019

Mechanisms Of Type-I Ifn Inhibition: Equine Herpesvirus-1 Escape From The Antiviral Effect Of Type-1 Interferon Response In Host Cell, Fatai S. Oladunni

Theses and Dissertations--Veterinary Science

Equine herpesvirus-1 (EHV-1) is one of the most important and prevalent viral pathogens of horses causing a major threat to the equine industry throughout most of the world. EHV-1 primarily causes respiratory disease but viral spread to distant organs enables the development of more severe sequelae; abortion and neurologic disease. In order to produce disease, EHV-1 has to overcome the innate barrier of the type-I interferon (IFN) system in host cells. However, the underlying mechanisms employed by EHV-1 to circumvent the type-I IFN response in host cells are not well understood. In this project study, using molecular techniques, we explored ...


Automatic 13C Chemical Shift Reference Correction Of Protein Nmr Spectral Data Using Data Mining And Bayesian Statistical Modeling, Xi Chen Jan 2019

Automatic 13C Chemical Shift Reference Correction Of Protein Nmr Spectral Data Using Data Mining And Bayesian Statistical Modeling, Xi Chen

Theses and Dissertations--Molecular and Cellular Biochemistry

Nuclear magnetic resonance (NMR) is a highly versatile analytical technique for studying molecular configuration, conformation, and dynamics, especially of biomacromolecules such as proteins. However, due to the intrinsic properties of NMR experiments, results from the NMR instruments require a refencing step before the down-the-line analysis. Poor chemical shift referencing, especially for 13C in protein Nuclear Magnetic Resonance (NMR) experiments, fundamentally limits and even prevents effective study of biomacromolecules via NMR. There is no available method that can rereference carbon chemical shifts from protein NMR without secondary experimental information such as structure or resonance assignment.

To solve this problem, we ...


Development And Evaluation Of Nonradioactive Methods For Monitoring T Lymphocyte Response To Equine Arteritis Virus (Eav) In Horses, Annet Kyomuhangi Jan 2019

Development And Evaluation Of Nonradioactive Methods For Monitoring T Lymphocyte Response To Equine Arteritis Virus (Eav) In Horses, Annet Kyomuhangi

Theses and Dissertations--Veterinary Science

Target cell lysis is the hallmark of immune effector responses of cytotoxic T lymphocytes (CTL), natural killer (NK) cells, and monocytes. The most commonly used assay to measure target cell lysis is the 51Cr release assay and is considered the ‘gold standard’. However, this assay has many disadvantages that limit its use by most laboratories. Thus, several alternative assays have been developed. Some of these alternative assays are more sensitive, easy to perform and do not use radioactive elements.

In this study, four of these assays were evaluated for their ability to detect antigen- specific CTL responses in equine blood ...


Modulation Of Inflammatory Cytokine, Chemokine, And Toll-Like Receptor Genes And Transcriptome Analysis Of Equine Endothelial Cells Following Infection With Equid Herpesvirus-1, And Equine Arteritis Virus., Saranajith Wangisa Dunuwille Jan 2019

Modulation Of Inflammatory Cytokine, Chemokine, And Toll-Like Receptor Genes And Transcriptome Analysis Of Equine Endothelial Cells Following Infection With Equid Herpesvirus-1, And Equine Arteritis Virus., Saranajith Wangisa Dunuwille

Theses and Dissertations--Veterinary Science

EHV-1 is a double-stranded DNA virus whereas EAV is a positive sense, single-stranded RNA virus. Therefore, genetically, they are very different from one another. However, both these viruses are endotheliotropic and thus, infect and replicates in equine endothelial cells resulting in vasculitis. Vasculitis is central to the pathogenesis of these two viruses. Thus, the main objective of this thesis was to investigate the inflammatory and innate immune responses of EECs that contribute towards the development of vasculitis following infection with EHV-1 and EAV in-vitro. Since proinflammatory cytokines and chemokines produced by endothelial cells play a significant role in the development ...


Evolution Of The Zhx Transcription Factor Family And Analysis Of Zhx2 Target Genes Cyp2a4 And Cyp2a5 In Mouse Liver, Alexandra Nichole Nail Jan 2019

Evolution Of The Zhx Transcription Factor Family And Analysis Of Zhx2 Target Genes Cyp2a4 And Cyp2a5 In Mouse Liver, Alexandra Nichole Nail

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

The liver is the largest internal organ and performs a wide variety of functions to maintain organismal homeostasis. While some liver functions are carried out by all hepatocytes, other functions are restricted to certain populations of hepatocytes within the liver. This phenomenon, called zonal gene regulation or liver zonation, controls may metabolic processes within the liver including ammonia detoxification; glucose homeostasis; bile acid and glutamine synthesis; and metabolism of xenobiotics, lipids, and amino acids. The liver also expresses many genes in a developmental or sex-biased manner. Some genes are expressed at higher levels early or late in development, or alternatively ...


Agricultural Livelihoods In Harlan County: A Case Study Approach Of Two Farms, Heather Kinney Jan 2019

Agricultural Livelihoods In Harlan County: A Case Study Approach Of Two Farms, Heather Kinney

Theses and Dissertations--Community & Leadership Development

This thesis explores agricultural livelihoods in Harlan County with two case studies in order to challenge dominant narratives about Eastern Kentucky. Harlan County, and Appalachia more broadly, is often written about in terms of its relationship to extractive industries. Absentee landownership in Appalachia has been well documented, especially in the case of coal counties. However, the relationship between extraction and agricultural livelihoods in Appalachia warrants more attention. The story of agricultural livelihoods in the region is often pushed to the periphery much like the practices of “hillside” farming. While geography makes much of the land unsuitable for farming in Harlan ...


The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback Jan 2019

The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback

Theses and Dissertations--Biology

The ketogenic diet is commonly used to control epilepsy, especially in cases when medications cannot. The diet typically consists of high fat, low carb, and adequate protein and produces a metabolite called acetoacetate. Seizure activity is characterized by glutamate excitotoxicity and therefore glutamate regulation is a point of research for control of these disorders. Acetoacetate is heavily implicated as the primary molecule responsible for decreasing glutamate in the synapse; it is believed that acetoacetate interferes with the transport of glutamate into the synaptic vesicles. The effects on synaptic transmission at glutamatergic synapses was studied in relation to the ketogenic diet ...


Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks Jan 2019

Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks

Theses and Dissertations--Biology

Plants are threatened by global change, increasing variability in weather patterns, and associated abiotic stress. Consequently, there is an urgent need to enhance our ability to predict plant community dynamics, shifts in species distributions, and physiological responses to environmental challenges. By building a fundamental understanding of plant stress tolerance, it may be possibly to protect the ecological services, economic industries, and communities that depend on plants. Dehydration tolerance (DhT) is an important mechanism of water stress tolerance with promising translational applications. Here, I take advantage natural variation in DhT to gain a deeper insight into this complex trait. In addition ...


Computational Tools For The Dynamic Categorization And Augmented Utilization Of The Gene Ontology, Eugene Waverly Hinderer Iii Jan 2019

Computational Tools For The Dynamic Categorization And Augmented Utilization Of The Gene Ontology, Eugene Waverly Hinderer Iii

Theses and Dissertations--Molecular and Cellular Biochemistry

Ontologies provide an organization of language, in the form of a network or graph, which is amenable to computational analysis while remaining human-readable. Although they are used in a variety of disciplines, ontologies in the biomedical field, such as Gene Ontology, are of interest for their role in organizing terminology used to describe—among other concepts—the functions, locations, and processes of genes and gene-products. Due to the consistency and level of automation that ontologies provide for such annotations, methods for finding enriched biological terminology from a set of differentially identified genes in a tissue or cell sample have been ...


Computational Tools For The Untargeted Assignment Of Ft-Ms Metabolomics Datasets, Joshua Merritt Mitchell Jan 2019

Computational Tools For The Untargeted Assignment Of Ft-Ms Metabolomics Datasets, Joshua Merritt Mitchell

Theses and Dissertations--Molecular and Cellular Biochemistry

Metabolomics is the study of metabolomes, the sets of metabolites observed in living systems. Metabolism interconverts these metabolites to provide the molecules and energy necessary for life processes. Many disease processes, including cancer, have a significant metabolic component that manifests as differences in what metabolites are present and in what quantities they are produced and utilized. Thus, using metabolomics, differences between metabolomes in disease and non-disease states can be detected and these differences improve our understanding of disease processes at the molecular level. Despite the potential benefits of metabolomics, the comprehensive investigation of metabolomes remains difficult.

A popular analytical technique ...


The Functional Role Of Rna Binding Protein Rbms3 As A Tumor Promoter In Triple-Negative Breast Cancer Cells, Yuting Zhou Jan 2019

The Functional Role Of Rna Binding Protein Rbms3 As A Tumor Promoter In Triple-Negative Breast Cancer Cells, Yuting Zhou

Theses and Dissertations--Molecular and Cellular Biochemistry

RBMS3 belongs to the family of c-myc gene single-strand binding proteins (MSSPs) that play important roles in transcriptional regulation. Here, we show that RBMS3 functions as a tumor promoter in triple-negative breast cancer (TNBC), a highly aggressive BC subtype. Analysis of RBMS3 expression shows that RBMS3 is upregulated at both mRNA and protein levels in TNBC cells. Functionally, overexpression of RBMS3 increases cell migration, invasion and cancer stem cell (CSC) behaviors. Moreover, RBMS3 induces expression of epithelial-mesenchymal transition (EMT) and CSC markers. Conversely, loss of RBMS3 in TNBC BT549 cells inhibits cell proliferation, migration and mesenchymal phenotype. Correlation analysis shows ...


Factors That Influence Maternal Feeding Decisions For Toddlers: Extending The Theory Of Planned Behavior, Elizabeth Lucas Combs Jan 2019

Factors That Influence Maternal Feeding Decisions For Toddlers: Extending The Theory Of Planned Behavior, Elizabeth Lucas Combs

Theses and Dissertations--Kinesiology and Health Promotion

Establishing healthy eating behaviors is vital in the early years to help combat the development of obesity and other chronic diseases. Mothers play an invaluable role in shaping their children's eating habits through controlling what and when children eat as well as the overall food environment, which is why a better understanding of what influences mothers’ decisions about these behaviors is important.

The purpose of the dissertation was to gain a better understanding of what impacts maternal feeding decisions regarding toddler nutrition behaviors. This was a two-phased mixed methods study. The aim of the initial study was to explore ...


Heart Rate Dynamics During And After Simulated Fire Ground Tasks: Effects Of Physical Fitness And Training, Anssi Ilmari Saari Jan 2019

Heart Rate Dynamics During And After Simulated Fire Ground Tasks: Effects Of Physical Fitness And Training, Anssi Ilmari Saari

Theses and Dissertations--Kinesiology and Health Promotion

Firefighting is a strenuous occupation that increases the risk of cardiovascular events. Greater levels of physical fitness and training improve firefighters’ occupational performance, but little is known whether they are related to lower physiological stress and recovery from fire ground tasks. Heart rate, heart rate recovery and heart rate variability have been used to evaluate physical stress in association with exercise and fire ground tasks. However, there is a paucity of research evaluating the effects of physical fitness and training on heart rate dynamics during a simulated fire ground test (SFGT). Therefore, the primary purposes of this study were to ...


Analysis Of Push-Up And Pull-Up Variants To Develop An Upper Extremity Model, Ashley Carlene Wimsett Jan 2019

Analysis Of Push-Up And Pull-Up Variants To Develop An Upper Extremity Model, Ashley Carlene Wimsett

Theses and Dissertations--Kinesiology and Health Promotion

Musculoskeletal Injuries are the most common cause of severe long-term pain and physical disability. Push-Ups and Pull-Ups are effective dynamic exercises that mimic high level function activities, such as those used in the military. The model developed allows for researchers to analyze the forces and moments associated with the shoulder, elbow and wrist, to further assess function in military personnel, athletes and the active population. The model also follows the guidelines set forth by the International Society of Biomechanics (ISB).


An Examination Of The Effects Of Bilateral And Unilateral Very Short-Term Dcer Training On Strength And Neuromuscular Responses Within The Lower Limb Bilateral Deficit, Mark Travis Byrd Jan 2019

An Examination Of The Effects Of Bilateral And Unilateral Very Short-Term Dcer Training On Strength And Neuromuscular Responses Within The Lower Limb Bilateral Deficit, Mark Travis Byrd

Theses and Dissertations--Kinesiology and Health Promotion

The very short-term resistance training (VST) model, utilizing only 2-3 training sessions, has been used to examine early phase skeletal muscle, neural, and performance adaptations. The VST model has previously been used to examine these early phase adaptations in bilateral and unilateral, isometric, isokinetic, and dynamic muscle actions in the limbs of the upper- and lower-body. The bilateral deficit (BLD) is a phenomenon in which the sum of the forces produced unilaterally is greater than the force produced bilaterally during maximal contraction of the limbs. The appearance of a bilateral deficit has been be related to various factors; including training ...


Forage Quality Of Cool Season Perennial Grass Horse Pastures In The Transition Zone, Annmarie Christine Riley Jan 2019

Forage Quality Of Cool Season Perennial Grass Horse Pastures In The Transition Zone, Annmarie Christine Riley

Theses and Dissertations--Plant and Soil Sciences

Cool season perennial grasses are the foundation of equine nutrition in the transition zone. The objective of this study was to evaluate forage quality using ADF, NDF, IVTDMD, CP, WSC, and ESC and changes in vegetative swards seasonally, diurnally, across species (Kentucky bluegrass, tall fescue, orchardgrass, and perennial ryegrass) and cultivar. This study was conducted in 2015 and 2017 and plots were maintained vegetatively with two to four week mowing. Morning and afternoon sample collection occurred monthly during the growing season. Samples were flash frozen; freeze dried, ground, and scanned using Near Infrared Reflectance Spectroscopy (NIRS) to predict forage quality ...


Enhanced Efficiency Nitrogen Formulation Effect On Grass-Legume Pasture Productivity, Kathryn Marie Payne Jan 2019

Enhanced Efficiency Nitrogen Formulation Effect On Grass-Legume Pasture Productivity, Kathryn Marie Payne

Theses and Dissertations--Plant and Soil Sciences

The use of nitrogen (N) fertilizer is generally restricted on mixed species forage systems due to its stimulatory effect on grasses which increases competition with legume species. Reduced legume growth from this competition can compromise forage nutritive value and prospective yields. The controlled-release nature of several enhanced efficiency fertilizer N products holds the potential to improve legume persistence in mixed species pastures while providing supplemental N required by the grass component. The studies contained in this dissertation evaluated the effect of different enhanced efficiency N formulations (ATU, ESN, methylene urea, SuperU, and a 75% ESN: 25% urea blend) and untreated ...


Tgf-Β, Wnt, And Fgf Signaling Pathways During Axolotl Tail Regeneration And Forelimb Bud Development, Qingchao Qiu Jan 2019

Tgf-Β, Wnt, And Fgf Signaling Pathways During Axolotl Tail Regeneration And Forelimb Bud Development, Qingchao Qiu

Theses and Dissertations--Neuroscience

Tgf-β, Wnt, and Fgf signaling pathways are required for many developmental processes. Here, I investigated the requirement of these signaling pathways during tail regeneration and limb development in the Mexican axolotl (Ambystoma mexicanum).

Using small chemical inhibitors during tail regeneration, I found that the Tgf-β signaling pathway was required from 0-24 and 48-72 hours post tail amputation (hpa), the Wnt signaling pathway was required from 0-120 hpa, and the Fgf signaling pathway was required from 0-12hpa. Tgf-β1 was upregulated after amputation and thus may mediate Tgf-β signaling pathway during tail regeneration. Both Smad-mediated and non-Smad mediated Tgf-β signaling were activated ...


Circadian Rhythm Phase Shifts Caused By Timed Exercise Vary With Chronotype In Young Adults, J. Matthew Thomas Jan 2019

Circadian Rhythm Phase Shifts Caused By Timed Exercise Vary With Chronotype In Young Adults, J. Matthew Thomas

Theses and Dissertations--Kinesiology and Health Promotion

The circadian system controls 24-hour cycles of behavior and physiology, such as rest-activity and feeding rhythms. The human circadian system synchronizes with, or entrains to, the light/dark cycle (sunrise/sunset) to promote activity and food consumption during the day and rest at night. However, strict work schedules and nighttime light exposure impair proper entrainment of the circadian system, resulting in chronic circadian misalignment. Numerous studies have shown that chronic circadian misalignment results in poor health. Therefore, therapeutic interventions that could shift circadian rhythms and alleviate circadian misalignment could broadly impact public health. Although light is the most salient time ...


Effects Of Agricultural Loans In Developing Countries – Benin Case Study, Nicaise S. M. Sagbo Jan 2019

Effects Of Agricultural Loans In Developing Countries – Benin Case Study, Nicaise S. M. Sagbo

Theses and Dissertations--Agricultural Economics

Limited access to financial services is known as a major constraint to agricultural development (FAO, 2002). Farmers need liquidity to face agricultural expenses throughout the production cycle but mainly at the beginning. Mainstream financial institutions are reluctant to serve the agricultural sector for several reasons. First, they consider the sector to be highly risky with low performance. Also, agricultural activities depend on the weather, they take place in remote rural areas, and commodities prices are volatile. All these aspects make it hard for standard banks to reach their profit goals when lending to farmers. Since microfinance was conceived, it has ...


Evaluating Water Management Policy In Saudi Arabia Using A Bilevel, Multi-Objective, Multi-Follower Programming Approach, Jawad Alhashim Jan 2019

Evaluating Water Management Policy In Saudi Arabia Using A Bilevel, Multi-Objective, Multi-Follower Programming Approach, Jawad Alhashim

Theses and Dissertations--Agricultural Economics

Over the past five decades, the Saudi government has adopted many agricultural policies aimed to: achieve self-sufficiency of food, increase the participation of the agricultural sector in the economy, and reduce the consumption of irrigation water. Due to conflicts among government objectives and the incompatibility of farmers' objectives with those of some agricultural policies, the government has not been able to fully achieve its objectives.

To accomplish its goals the government, or decision maker needs to understand the farmer, or follower, reaction when s/he adopts a new decision. The dissertation aims to build a model that achieves government goals ...


Utilizing Large Scale Datasets To Evaluate Aspects Of A Sustainable Bioeconomy, Gwanseon Kim Jan 2019

Utilizing Large Scale Datasets To Evaluate Aspects Of A Sustainable Bioeconomy, Gwanseon Kim

Theses and Dissertations--Agricultural Economics

This dissertation combines large scale datasets to evaluate crop prediction, land values, and consumption of a crop being considered to advance a sustainable bioeconomy. In chapter 2, we propose a novel application of the multinomial logit (MNL) model to estimate the conditional transition probabilities of crop choice for the state of Kentucky. Utilizing the recovered transition probabilities the forecast distributions of total acreages for alfalfa, corn, soybeans, tobacco, and wheat produced in the state from 2010 to 2015 can be recovered. The Cropland Data Layer is merged with the Common Land Unit dataset to allow for the identification of crop ...


Three Essays On Saudi Arabia Agricultural Markets, Yosef Abdulrahman Alamri Jan 2019

Three Essays On Saudi Arabia Agricultural Markets, Yosef Abdulrahman Alamri

Theses and Dissertations--Agricultural Economics

The first essay compares six common models, linear, quadratic, Cobb-Douglas, translog, logarithmic, and transcendental, to estimate wheat yield and area functions for Saudi Arabia. Data cover 1990-2016 for all the variables that affect wheat supply. After testing the models using Box-Cox, multicollinearity, and autocorrelation tests, we decide that the Cobb-Douglas models provide the best fit for both yield and area. We find the price elasticity of wheat is inelastic. Yield price elasticities are more inelastic than area elasticities. The impact of government policy number 335 has a larger effect on area than yield. The cultivated area of wheat, the one-year ...


Two Essays On Input Substitution And Optimal Decision Making In Crop And Livestock Production Systems, John T. Allison Jr. Jan 2019

Two Essays On Input Substitution And Optimal Decision Making In Crop And Livestock Production Systems, John T. Allison Jr.

Theses and Dissertations--Agricultural Economics

The thesis presented consists of two essays that analyze input substitution and decision making in crop and livestock production systems. The first essay consists of a whole-farm analysis that sought to optimize feed mixes and enterprise combinations for an organic dairy operation in the Southeastern United States. This was accomplished through mathematical programming where whole-farm net returns were maximized, and total feed costs were minimized simultaneously for four milk production level cases. Additionally, the sensitivity of the system and break-even milk price were explored. Results suggest substitutability in ration components where an increase in supplemental feeds is justified by additional ...


Forms Of Supplemental Selenium In Vitamin-Mineral Mixes Differentially Affect Serological And Hepatic Parameters Of Growing Beef Steers Grazing Endophyte-Infected Tall Fescue, Yang Jia Jan 2019

Forms Of Supplemental Selenium In Vitamin-Mineral Mixes Differentially Affect Serological And Hepatic Parameters Of Growing Beef Steers Grazing Endophyte-Infected Tall Fescue, Yang Jia

Theses and Dissertations--Animal and Food Sciences

Consumption of endophyte-infected tall fescue results in a syndrome of negatively altered physiological systems, collectively known as fescue toxicosis. Another challenge to endophyte-infected tall fescue -based beef cattle operations is that the soils often are selenium (Se) poor, necessitating the need to provide supplemental Se. To test the general hypothesis that different forms of supplemental Se would ameliorate the negative effects of fescue toxicosis, predominately-Angus steers (BW = 183 ± 34 kg) were randomly selected from herds of fall-calving cows grazing an endophyte-infected tall fescue pasture and consuming vitamin-mineral mixes that contained 35 ppm Se as sodium selenite (ISe), SELPLEX (OSe), or ...


Relationships Between Animal Temperament And Systemic Immune Responses In Beef Cattle Exposed To Conditions Associated With Conventional Management, Alexander W. Altman Jan 2019

Relationships Between Animal Temperament And Systemic Immune Responses In Beef Cattle Exposed To Conditions Associated With Conventional Management, Alexander W. Altman

Theses and Dissertations--Animal and Food Sciences

Measures of temperament have been shown to influence physiological responses. Exit velocity (EV) has been identified as an objective, robust measure of temperament that can be used to predict subsequent performance of cattle. Additionally, previous studies from our lab indicate this measure of temperament may be related to production of interferon-γ (IFN-γ), a cytokine associated with cell-mediated immunity (CMI). Whereas research has investigated effects of EV upon immune responses, the overall goal of these studies was to examine this relationship under a variety of scenarios including human handling, transportation, and exposure to endophyte-infected tall fescue (E+) for determination of its ...