Research Methods in Life Sciences Commons^™

Microfabrication And Electrochemical Characterization Of A Novel Su-8 Probe With An Array Of Individually Addressable Electrodes Suitable For Redox Cycling Experiments In Ultra-Small Volumes, Mahsa Lotfi Marchoubeh

Graduate Theses and Dissertations

Redox cycling is an electrochemical technique that utilizes closely spaced generator and collector electrodes to cycle reversible redox species between their oxidative states. With advantages in signal amplification, selectivity of species based on their electrochemical reaction mechanism, and limited or no background subtraction, this technique is well suited for selective detection of important electrochemically active molecules such as dopamine at basal or slowly changing levels.

Miniaturized medical devices have become an area of great interest for measurement of chemicals in limited volumes with low concentrations or in sensitive tissues. A probe on a polymeric SU-8 substrate with suitable dimensions and …

Survey Of Ticks And Tick-Borne Pathogens Associated With Feral Swine (Sus Scrofa) In Arkansas, Haylee Campbell

Graduate Theses and Dissertations

Feral hogs (Sus scrofa L.) are an invasive species throughout the southeast United States and found in every Arkansas county. As feral hogs invade new habitat, they can disrupt ecosystems, damage agriculture systems, and bring ticks and tick-borne pathogens with them. There are no surveys of the tick species parasitizing the Arkansas feral hog populations or the pathogens they carry. This is a public health concern because feral hogs occupy often same geographical regions as humans and livestock and can harbor over 45 animal diseases and parasites. The ticks carried by feral hogs can carry tick-borne pathogens that can cause …

Role Of Reptile-Invertebrate Interactions In Enigmatic Reptile Declines, Meredith Swartwout

Graduate Theses and Dissertations

Reptile populations are declining world-wide and the mechanisms behind many of these declines remain enigmatic. Food web interactions (i.e., reduced prey availability or increased predation) have been implicated behind some reptile declines. However, relatively little is known about predation on lizard and snake eggs, despite egg survival being important for population dynamics of some species. Ants are important predators of squamate reptile eggs in tropical and temperate systems. In Costa Rica, long-term declines in terrestrial anole lizards were linked with reduced leaf litter depth, a factor that could influence egg vulnerability to ant predation. Fire ants (genus Solenopsis) are aggressive …

Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas

Graduate Theses and Dissertations

Monitoring biodiversity, to include its relative dispersal and contraction, has become a conservation task of great importance, particularly given the catastrophic and ongoing loss of habitat due to climate change. However, the timing, direction, and magnitude of these rates vary across taxa and ecosystems. Predicting specific impacts of climate change can thus be difficult and this, in turn, hampers management action. Metrics are needed to not only quantify contemporary requirements of species, but also predict potential distributions that fluctuate in lockstep with climate.

Montane ecosystems in the Himalayas are highly impacted by climate change, yet remain largely understudied due to …

Influence Of Local- And Landscape-Scale Factors On Avian Assemblage In Fragmented Tallgrass Prairie Landscape, Pooja Panwar

Graduate Theses and Dissertations

Agricultural expansion and increasing urbanization are driving rapid landscape modification in the Tallgrass prairies ecosystem and are affecting biodiversity at multiple spatial scales. Thus, the conservation of fragmented grassland and steeply declining grassland avifauna is dependent on the relationship between local- and landscape-scale factors and avian assemblage. We also need to understand how these factors, operating at different spatial scales, drive the occupancy of different guilds in the assemblage. We conducted repeated point count surveys during the breeding season of 2019 at 66 grassland sites across Arkansas and Missouri, USA. We developed a multi-species occupancy model to estimate species richness, …

Evaluation Of Nutritional Factors That Influence The Efficacy Of Tributyrin As A Feed Additive For Broilers, Brooke Bodle

Graduate Theses and Dissertations

Tributyrin (TB) is a glyceride ester of butyrate that has the potential to improve broiler performance and intestinal development. Therefore, to fully evaluate this potential, three experiments were conducted to evaluate effect of tributyrin (TB) on broiler growth performance, nutrient digestibility, carcass characteristics, intestinal morphology, and gastrointestinal function in birds fed diets varying in composition reared in battery cages and floor pens. Experiment 1 explored the supplementation of graded doses of TB and its impact upon growth performance, nutrient digestibility, and carcass characteristics in a step-down program when added to a reduced energy and amino acid diet. A linear reduction …

Quantifying The Leaching Of Nutrients And Metals In A Pasture Soil As Affected By Excreta Of Ruminants Fed Alternative Diets, Ian Kennedy

Graduate Theses and Dissertations

The leaching of nitrate through the soil profile and into adjacent water systems has been a leading cause of water pollution and results in the loss of a valuable nutrient from animal production systems. Forage-based animal production systems may be improved through manipulation of animal diets that incorporate tannins and total polyphenolic compounds with feed, increasing the amount of nitrogen (N) retained by an animal/decreasing rates of digestion and altering the N-containing compounds that are excreted and deposited onto soil. Incorporating the forage legumes sericea lespedeza (Lespedeza cuneate [Dumont de Courset] G. Don) and lablab (Lablab purpurues L.) into the …

Relationship Of Underline Scores And Production Traits In Beefmaster Cattle, Bryan R. Kutz

Graduate Theses and Dissertations

The objective of this study was to establish the relationship of underline scores (UDLS), production traits, and conformation scores in Beefmaster cattle born between 1976 through 2008. Records provided by Beefmaster Breeders United (BBU) were analyzed. Certified classifiers approved by the BBU recorded scores. Sizes and shapes of the underlines differentiated the scores (1-4). A score of one was used to designate the least amount of navel flap or sheath and a score of four represents the maximum amount of naval flap or sheath accepted for registration in the BBU. In this study the relationship of the traits was determined …

Methods To Reducing Weaning Stress In Early Weaned Spring Beef Calves, Matthew Daniel Hahn

Graduate Theses and Dissertations

Reducing weaning stress in beef calves can have dramatic benefits to the health, growth, and performance to beef calves post-weaning. Studies have shown that providing creep feed to calves during the pre-weaning period can improve their nutritional status, which can better prepare them for the stresses they will be exposed to during the weaning process. Studies have also shown that two-stage weaning can reduce the stresses associated with weaning. Previous research has suggested that this method resulted in dramatic changes in behavioral signs associated with stress. The objective of this study was to evaluate the effects of two-stage weaning with …

Pathogenicity Of Staphylococcus Agnetis Associated With Lame Broilers With Osteomyelitis, Sura Faris Salih Zaki

Graduate Theses and Dissertations

We developed High Resolution Melt Analysis (HERMA) as a rapid and reliable molecular diagnostic assay for the detection and identification of the main bacterial species recovered from the blood and lesions of bacterial chondronecrosis with osteomyelitis (BCO) from the lame broilers at the University of Arkansas poultry research farm. Also, the present study confirms that raising young birds on suspended wire flooring has been proved to successfully induce lameness attributable to BCO with birds being more susceptible to bacteraemia than those that were raised on litter flooring. The newly described pathogen, Staphylococcus agnetis, has been reported to be overrepresented in …

Examining Pathogenesis And Preventatives In Spontaneous And Staphylococcus-Induced Bacterial Chondronecrosis With Osteomyelitis In Broilers, Nnamdi Simon Ekesi

Graduate Theses and Dissertations

Bacterial chondronecrosis with osteomyelitis is the most important cause of lameness in broilers. This is important to poultry production, as it poses animal welfare issues, and causes a significant loss in revenue. The remediation of this disease requires the study of its etiology with fitting models and evaluating preventatives. The research reported herein covers genomic virulence analysis of BCO isolates, mainly Staphylococcus aureus, and Escherichia coli retrieved from lame birds. We found that S. aureus isolates were closest to chicken strains in Europe but may have been in the Arkansas area for a decade. Phylogenomics suggest our S. aureus is …

Effects Of Long-Term Variation In Temperature On Reproductive Phenology In A Population Of Eastern Bluebirds (Sialia Sialis), Paul Pleiman

Graduate Theses and Dissertations

This study investigates the relationship between multiple temperature variables, to include annual and pre-lay date temperatures with first-egg and mean first-egg lay dates of the eastern bluebird at the Warner Parks in Nashville, Tennessee, USA. Data is collected by citizen scientists for the Eastern Bluebird Nesting Box Project while visiting artificial nest boxes throughout the park and recording observations made during the breeding season. Temperature data is retrieved from the Northwest Alliance for Computational Science and Engineering’s Parameter-elevation Regressions on Independent Slopes Model (PRISM) Climate Group, based at Oregon State University. The analyses showed no correlation between annual or pre-lay …

Fate And Dissemination Of Salmonella Reading In Market-Age Turkeys At Processing Using Oral Gavage Challenge Model, Aaron Ashcraft

Graduate Theses and Dissertations

This study aimed to evaluate the fate and dissemination of Salmonella Reading (SR) in market-age turkeys using an oral gavage challenge model. One hundred twenty-eight-week-old commercial turkey hens were moved from commercial production to research facilities. Upon arrival, a combination of enrofloxacin, 10 mg/kg, and florfenicol, 20 mg/kg, were orally administered sequentially before comingled placement on fresh pine shavings. Turkeys were challenged with 108 cfu SR by oral gavage on days 4 and 7 post-placement. Subsets were subjected to simulated commercial processing on days 14 (n=40), 21 (n=40) and 28 (n=32) post-placement (corresponding to 10, 11, and 12 weeks of …

Evaluation Of Selected Bacillus Direct-Fed Microbial Candidates In Reduced Energy Diets On Live Performance, Carcass Characteristics, And Foot Pad Dermatitis, Kyle Teague

Graduate Theses and Dissertations

Bacillus spp. are ubiquitous, Gram-positive, spore forming bacteria that are commonly recovered from the environment and gastrointestinal tract (GIT) of poultry. These spores are capable of withstanding harsh condition such as feed pelletization, which facilitates inclusion in poultry feeds. Once ingested by the bird, spores germinate into metabolically active vegetative cells which can produce extracellular enzymes which can hydrolyze otherwise indigestible components of the feed. Soybean meal (SBM) is the gold standard vegetable protein source for non-ruminant animals worldwide and is included in practically all poultry diets in the United States at levels ranging from 10 to more than 30%. …

Effect Of Feed Additives And Toxic Elements On Swine Growth Performance, Nutrient Digestibility, Immune Function And Reproductive Performance, Richard A. Mudarra Hernández

Graduate Theses and Dissertations

To evaluate the effects of peptide in combination of zinc oxide (Zno) or acidifiers (Exp 1), and gossypol (G) from cottonseed meal (CSM) ( Exp 2&3) on growth performance, complete blood cell counts (Exp 1, 2&3), nutrient digestibility (Exp 1), plasma gossypol (Exp 2&3) and semen quality (Exp 3), weaned pigs (Exp 1), growing gilts (Exp 2) and growing boars (Exp 3) were randomly allotted to dietary treatments. Treatments for Exp 1 during phase 1&2 were: (1) Positive Control (PC), formulated to meet NRC (2012) nutrient requirements; (2) Negative control (NC), fish meal was reduced to achieve -0.13% SID lysine; …

Evaluation Of Different Ensiling Methods On Storage And Feeding Value Of The Residual Material From Edamame Soybean Processing, Ellen Herring

Graduate Theses and Dissertations

Use of organic waste material by ruminant animals from food processing operations potentially reduces costs and reduces environmental issues from disposal of these residues. Therefore, 2 experiments were conducted to evaluate the storage and feeding value of residual from edamame soybean processing for ruminant animals. Two types of waste streams, waste during harvest time and waste from processing stored material, were ensiled (on a laboratory scale) using various methods and effects on post-ensiling nutritive value were examined. Material from both waste streams were ensiled either without wilting or after wilting; each moisture level was ensiled with and without an inoculant. …

Effects Of Commercial Feed Additives On Growth Performance And Gut Microbiota Of Nursery Pigs, Xiaoyuan Wei

Graduate Theses and Dissertations

To secure animal welfare and maximum production, feed additives are often added to nursery pig diets to increase nutrition digestibility, enhance intestinal health, and prevent or mitigate disease, with the ultimate goal of improving growth performance. This thesis performed a longitudinal analysis using next-generation sequencing to investigate the dynamic changes of gut microbiota in weaned pigs fed commercial feed additives. Chapter II was used to evaluate the effects of organic acid mixture on growth performance and gut microbiota of weaning pigs. This study demonstrated that the inclusion of 0.035% (SBA0.035) or 0.070% (SBA0.070) sodium butyrate in a diet containing 0.5% …

Biogeography Of The Bovine Respiratory Microbiome And Its Relationship With Bovine Respiratory Disease, Jianmin Chai

Graduate Theses and Dissertations

Bovine respiratory disease (BRD) is the most common and costly disease in the beef cattle industry, leading to high morbidity, mortality and huge economic loss. Despite the recent advances in vaccination and antimicrobial techniques, no significant health-improved outcomes have developed. Due to a deep investigation of the microbiome, respiratory microbiotas are known to have important roles for host health and disease. However, BRD specific pathogens have not yet been identified since they are found in both healthy and diseased animals. A systemic and comprehensive study of the biogeography of the bovine respiratory microbiome and its relationship with BRD is lacking …

Respiratory Chain Activity And Protein Expression In Skeletal Muscles From High And Low Feed Efficient Swine Within The Same Genetic Line, Earsie L. Alcorn De Feliz

Graduate Theses and Dissertations

Current as well as past studies have provided evidence for a connection between macroeconomic/agricultural and cellular/biochemical basis of feed efficiency (FE; gain:feed) in farm animal production. Our investigation of respiratory chain activity, mitochondrial protein oxidation and protein expression was an expansion to the subcellular/molecular level. In this study we investigated the entire complex (Cx) of the electron transport chain (ETC) for differences in Cx activities in mitochondria isolated from skeletal muscle in high (HFE) and low (LFE) feed efficient swine within the same genetic line. Review of literature provided information for the connection between feed efficiency, mitochondrial function, and muscle …

Mitochondrial Contributions To Disuse Atrophy: Let’S Talk About Sex, Megan Rosa-Caldwell

Graduate Theses and Dissertations

Skeletal muscle atrophy is a hallmark of many pathologies and is associated with disease prognosis, quality of life, and mortality. Specifically, lack of contractile activity of the muscle can result in disuse-associated atrophy. Disuse-induced atrophy is a common phenomenon in intensive care unit (ICU) patients and significantly impacts patient prognosis and ability to transition of out of intensive care. However, effective therapeutics to mitigate disuse-associated atrophy do not exist, clearly demonstrating the scientific and clinical need to further understand mechanisms contributing to disuse atrophy. In particular, a significant portion of the scientific literature has utilized male models, yet there is …

Effects Of Supplementing Crystalline L-Valine And L-Isoleucine And A Novel Threonine Biomass In Reduced Crude Protein Diets Fed To Broilers, Derrell Trevor Lee

Graduate Theses and Dissertations

Poultry nutritionists continue to identify methods to lower feed price without compromising broiler growth performance, processing yields, or animal well-being. A common approach is to reduce dietary crude protein (CP), the second most expensive component in a broiler diet. Subsequently, reducing CP will reduce the inclusion levels of intact protein sources (e.g., soybean meal [SBM]), which can be accomplished by supplementing individual amino acids (AA). This methodology not only reduces diet cost, pending if feed-grade AA are more economical, but can contribute to improving broiler health and environmental sustainability. Therefore, two experiments were conducted to evaluate individual feed-grade AA in …

Distillers Dried Grains With Solubles: Determination Of Metabolizable Energy Values Using Regression-Based Assays And Their Correlation With Chemical Composition, Kenia Mitre

Graduate Theses and Dissertations

The inherent variability and lack of standardization of in vivo assays to determine the metabolizable energy (ME) of DDGS has led to inconsistent values and limited its potential to use in broiler diets. Therefore, two experiments were conducted to characterize the content of nitrogen-corrected ME (MEn) in 11 DDGS sources obtained from various ethanol plants using a regression-based broiler assay and to attempt to develop equations to predict MEn based on its chemical composition. In experiment 1, the objectives were to determine the influence of inclusion level and feed intake on the resulting ME and MEn values of a single …

Nutritional Strategies For Feeding Broiler Breeders On Hen And Progeny Performance, Antonio Beitia

Graduate Theses and Dissertations

Over the last 60 plus years, broiler breeders have been under an incredible amount of genetic pressure. This genetic pressure comes from the continually increasing consumer demand for poultry products. The objective of this dissertation is to understand the effects of different nutritional and management practices on broiler breeder’s performance. The first series of experiments investigate the impact of broilerization on hen and early progeny performance. Broilerization is a process only used by genetic companies. The results from these experiments showed the adverse effects of broilerization on chick quality and hen performance. Follow up trials were performed to determine the …

Effect Of The Prospect Of Transport On Captive Tiger Behavior And Fecal Cortisol In Naïve And Experienced Tigers, Callan Lichtenwalter

Graduate Theses and Dissertations

With close to 5,000 captive tigers in the United States, it is vital to ensure that these tigers are receiving adequate welfare whether they are in an accredited facility, or privately owned. The goal of this study was to assess whether captive tigers at a rescue facility with experience being transported outside of the facility would respond differently to the presentation of their transport vehicle than their naïve counterparts who had only been transported within the facility. The behavior of 5 naïve and 7 experienced tigers (n = 12) located at Turpentine Creek Wildlife Refuge in Eureka Springs, Arkansas was …

The Effects Of Excess Dietary Sulfur Using Supplemental Sodium Sulfate On Beef Steer, Heifer, And Progeny Productive And Physiological Responses, Jamie Hawley

Graduate Theses and Dissertations

For studies 1 through 3, 20 steers of predominantly Angus breeding, were stratified by body weight (279 ± 13.2 kg), assigned randomly to 6 paddocks, and fed a low S ground corn and soybean meal supplement that did not contain any byproduct feeds (0.31% total dietary S; LS) or LS supplement with an additional 0.25% S provided from sodium sulfate (Na2SO4; 0.58% total dietary S; HS) for a 114-d growing phase. Steers were moved to feedlot (373 ± 0.2 kg), remained on prior dietary S treatments, and fed corn and soybean meal diets (0.19 and 0.42% total dietary S; LS …

Quantifying Greenhouse Gas Emissions And Ammonia Volatilization From Soil Amended With Excreta From Ruminants Fed Alternative Forage-Based Diets, Samuel Park

Graduate Theses and Dissertations

Forage-based ruminant diets supplemented with condensed tannins or polyphenolic-containing legumes may alter nitrogen (N) metabolism in the animal and reduce gas emissions from soil receiving excreta. The objective of the study was to determine if soil receiving urine or manure from sheep fed forage diets supplemented with condensed tannin or polyphenolic-containing legumes would decrease N gas emissions. Two field trials were conducted: in the first trial, sheep were fed alfalfa (Medicago sativa L.) silage diets supplemented with 0, 9, 18, or 27% sericea lespedeza (Lespedeza cuneate [Dumont de Courset] G. Don) (n = 4). In the second trial sheep were …

Development Of Arkansas Net Energy Equation, Katie Hilton

Graduate Theses and Dissertations

The modern broiler is growing at a rapid rate generating tremendous amounts of heat. A sensitive Net Energy (NE) system is needed to measure body heat production (HP) generated primarily by daily maintenance and synthesis and degradation of myofibrillar and sarcoplasmic protein. The first two chapters present evaluation of the classic way to calculate NE versus a new methodology; the Arkansas NE (Ark NE) system, with birds from two genetic lines fed diets with different AA content or different ME content in two different environmental temperatures.

Utilizing together the Net Energy maintenance (NEm), determined from indirect calorimetry, and Net Energy …

Lesioning Of The Nucleus Of The Hippocampal Commissure Followed By Food Deprivation Stress In Birds Demonstrates Simultaneous Involvement In Both The Hypothalamo-Pituitary-Adrenal Axis And The Hypothalamo-Pituitary-Thyroid Axis, Michael Thomas Kidd Jr.

Graduate Theses and Dissertations

The hypothalamo-pituitary-adrenal (HPA) axis is the regulatory system for the neuroendocrine stress response within vertebrates. Within the HPA axis corticotropin releasing hormone (CRH) is a major regulator and driving hormone. A structure named the nucleus of the hippocampal commissure (NHpC) has been found to contain CRH neurons and also these neurons respond to early food deprivation stress significantly prior to the paraventricular nucleus (PVN), the major driving nucleus of the classic neuroendocrine HPA axis. The objective of this study was to perform a knock down of the NHpC via electrolytic lesioning, thus eliminating a significant portion of its population of …

Evaluation Of Microbiome On Chicken Necrotic Enteritis And Growth Performance, Mussie Abraha

Graduate Theses and Dissertations

Necrotic enteritis (NE) has re-emerged following restriction of antimicrobial usage and costs $6 billion every year worldwide. The primary objective of the studies was to evaluate prevention and treatment of NE using a microbiota metabolic product, secondary bile acid deoxycholic acid (DCA), in drinking water. Day-old birds were tagged and placed in floor pens. In experiments 1 and 2, the birds were infected with Eimeria maxima (Em) at d 18 and C. perfringens at d 23 and 24 and the birds were euthanized at d 26. In experiment 3, birds were infected with Eimeria at d 20 and C. perfringens …

Detection Of Woody Breast Condition In Broiler Carcasses And Product Utilization In Further Processing, Juan Pablo Caldas Cueva

Graduate Theses and Dissertations

Woody Breast (WB) myopathy causes significant economic losses to the global poultry industry and the lack of objective, non-invasive and rapid methods for its detection as well as profitable alternatives for its utilization are contributing factors. This dissertation is divided into two main areas. The first area aimed to determine if there are carcass conformation changes that can be used to identify WB characteristics in commercial broilers using image analysis. In the first experiment, images of broiler carcasses were captured before evisceration to obtain and evaluate carcass measurements from the breast region. Eight image measurements and four ratios were used …