Research Methods in Life Sciences Commons^™

In Vitro And In Vivo Evaluation Of Antimicrobial Activity, Oocyst Sporulation Rate, Oocyst Integrity And Oocyst Infectivity In Eimeria Maxima M6 Oocyst Suspensions Treated With Chlorhexidine Salts In Comparison With Potassium Dichromate, Lauren Laverty

Graduate Theses and Dissertations

Eimeria species oocysts cause coccidiosis, one of the costliest diseases in the poultry industry. Coccidiosis infections cause significant economic losses due to reduced performance in chickens and turkeys. The objective of this thesis was to determine fecal bacterial recovery from chlorhexidine (CHX) salt suspensions containing Eimeria maxima M6 oocysts and evaluate the effect of CHX salts on oocysts during long-term cold storage. For bacterial recovery experiments, CHX digluconate and CHX gluconate were tested at different concentrations on poultry fecal slurries during oocyst shedding. Eimeria maxima M6 oocysts were evaluated in CHX salt suspensions to test the effect on oocyst degradation …

Assessment Of Dietary Energy And Amino Acid Diet Formulation In The Modern Broilers, Matheus Freitas Costa

Graduate Theses and Dissertations

As a result of the advancement of genetics, understanding broiler requirements for dietary energy and amino acids is essential for improving live performance and carcass characteristics. The energy system used to formulate diets in poultry is based on metabolizable energy (ME); this equation can be described as the total amount of energy in the feed minus gases and feces. However, the net energy (NE) system may be the best depiction of the energy utilized by birds for production and maintenance purposes once the heat increment (HI) is measured. Thus, a series of studies were conducted to establish the responsiveness of …

Evaluation Of The Virulence Potential Of Avian Pathogenic Escherichia Coli Isolated From Broiler Breeders With Colibacillosis In Mississippi, Jiddu Joseph

Theses and Dissertations

Avian pathogenic Escherichia coli (APEC) is a bacterium that is responsible for colibacillosis in birds. However, information about broiler breeder APEC isolates is limited, but the data is critical due to the transfer of this bacteria down the production pyramid to progenies resulting in high mortality. Therefore, we evaluated the phenotypic virulence characteristics of 28 isolates using embryo lethality and day-old chick challenge assays. Also, the in vitro adhesion and invasion potential of selected nine isolates were identified. Results showed more than 1/3^rd of the isolates were highly virulent and the virulence increased as the number of virulence-associated genes …

The Effect Of Spirulina Platensis Algae Inclusion In Feed Of Commercial Broilers Subjected To Cyclic Heat Stress, Kirsten Shafer

Graduate Theses and Dissertations

The effect of Spirulina platensis inclusion in feed of commercial broilers was evaluated over one experiment. The study aimed to investigate the effects of Spirulina platensis freshwater algae inclusion on live performance and processing characteristics of commercial broilers subjected to daily cyclic heat stress. Day old Ross 708 male broilers were placed into 8 environmentally controlled chambers. At d 21, four chambers remained on a control diet containing no algae (CON) while 4 chambers received a diet that included algae at an inclusion rate of 2.5% (ALG). An 8 hour daily cyclic heat stress (24°C to 36°C) was applied to …

Isolation Of Drug-Sensitive Eimeria Species From Wild Turkey Feces And Development Of A Model Bioshuttle Program For Eimeria Meleagrimitis For Domestic Turkeys, Maria Carolina Trujillo Peralta

Graduate Theses and Dissertations

The objective of this thesis was to determine the anticoccidial profile of Eimeria spp. derived from wild turkeys. These drug-sensitive Eimeria spp. have potential to be used as vaccine candidates to control coccidiosis in commercial turkeys. Chapter two consists of a brief literature review focused on coccidiosis in turkeys. Chapter three addresses the methodologies utilized to isolate, recover, and speciate Eimeria recovered from wild turkey feces in the eastern two-thirds of the United States. From this, we successfully obtained single oocyst-derived stocks for E. meleagrimitis, E. dispersa, E. meleagridis, E. gallopavonis, and E. adenoeides. Chapter four describes the experiment conducted …

Identification Of Possible Vectors For Histomoniasis In Turkeys On Commercial Farms In Arkansas And Oklahoma, Treva Dillon

Graduate Theses and Dissertations

Histomonas meleagridis, is a parasitic protozoan, commonly found in the gallinaceous species of birds and is the causative agent of Blackhead disease. The cecal worm, known as Heteraskis gallinarum, acts as a vector in the spread of H. meleagridis in gallinaceous birds. H. meleagridis develops inside the cecal worm and in its eggs which allows H. meleagridis a method to survive in the environment. Blackhead disease causes high mortality rates in both chickens and turkeys; however, turkeys are noted to have a higher mortality rate compared to chickens. Molecular diagnostic testing such as PCR has been developed by creating primers …

Optimization Of Clostridium Septicum Antigen Production And Evaluation Of Vaccine Administration Parameters For A Candidate Bacterin-Toxoid To Prevent Dermatitis In Commercial Turkeys, Aaron Forga

Graduate Theses and Dissertations

The objective of this thesis was to optimize the hemolytic activity of two isolates of Clostridium septicum to evaluate if hemolytic titer of C. septicum antigen at time of formalin inactivation corresponded to increased serum antibody titer to the C. septicum alpha-toxin of turkeys immunized with an experimental formalin inactivated bacterin-toxoid vaccine. Chapter 1 provides a brief overview of the thesis. Chapter 2 consists of a literature review focused on clostridial dermatitis, specifically C. septicum-associated dermatitis (cellulitis) that affects commercial turkeys. Chapter 3 outlines our attempts to optimize an experimental autogenous bacterin-toxoid vaccine as a potential strategy to mitigate clostridial …

Intestinal Microbiota Analysis Of Broiler Chickens Under Necrotic Enteritis Challenge And Tributyrin Supplementation, Taylor Nicole Mckinney

Graduate Theses and Dissertations

Poultry is a staple protein source for most of the planet. Until recently, antibiotic growth promoters (AGPs) were used to prevent illnesses in commercial chicken production. Currently, this is not possible due to regulations and consumer concern, but without such a preventative, diseases like necrotic enteritis (NE) have reemerged, posing a threat to bird health, and ultimately, our food source. Necrotic enteritis is a severe gastrointestinal disease caused by the gram-positive pathogen, Clostridium perfringens. Clinical features of this disease are diarrhea, intestinal lesions, and death, with a high transmission rate. In a subclinical form, growth performance is diminished and is …

The Role Of Microbiota On Campylobacter Jejuni Colonization And Growth Performance In Broiler Chickens, Ayidh Almansour

Graduate Theses and Dissertations

The successful poultry production at modern era comes from the vertical integratedindustrialization, which has fundamentally changed how animals have been living for millions of years. Antimicrobial growth promoters have been used to sustain the efficient industrialized animal production, driving antimicrobial overuse and resistance. Because of the increasing pressure from consumer’s concerns and government regulations, it is urgent to develop antimicrobial free alternatives as growth promoters in poultry production, but few effective antimicrobial alternatives are currently available. Campylobacter jejuni is one of the worldwide prevalent foodborne bacterial pathogens mainly transmitted from poultry. However, few mechanisms are available on why C. jejuni …

Investigating Molecular Mechanisms Behind Bacterial Chondronecrosis With Osteomyelitis (Bco) Pathogenesis In Modern Broilers, Alison Ramser

Graduate Theses and Dissertations

Bacterial chondronecrosis with osteomyelitis (BCO), a leading cause of lameness in broiler chickens, is characterized by infection, inflammation, and bone attrition. There are currently no effective treatments and positive diagnosis is only possible through necropsy evaluations. Lameness is also a rising animal welfare and economic concern, making prevention and detection of BCO all the more critical. These challenges are exacerbated by a lack of mechanistic understanding of BCO’s etiology. The question I asked during my dissertation was how bacteria induce bone attrition in BCO pathology. My research has shown that mitochondrial dysfunction is characteristic of BCO conditions along with autophagy …

Investigation Of Histomoniasis Prevention In Poultry, Lesleigh Beer

Graduate Theses and Dissertations

Histomonas meleagridis is the etiological agent of histomoniasis, also commonly known as blackhead disease. This protozoal disease of poultry is detrimental to turkeys with flock mortalities often reaching 80-100%, although other gallinaceous birds are susceptible. Since the voluntary removal of nitarsone in 2015, the poultry industry is suffering with no approved prophylactics, therapeutics, or vaccines for this disease. The objectives of this dissertation were to evaluate multiple methods for prevention or control of histomoniasis, including dietary chemoprophylaxis and vaccination. Specifically, this research evaluated quinine as a chemoprophylactic candidate (Chapter 3) or live-attenuated H. meleagridis as vaccine candidates (Chapter 4) in …

Reducing Dietary Crude Protein: Characterization Of Branched-Chain Amino Acid Antagonism In Modern Broiler Chickens, Craig William Maynard

Graduate Theses and Dissertations

Reducing the crude protein content of broiler diets while maintaining performance has been a primary research area in nutrition. During the late 20th century, the bulk of this research has involved supplementing broiler diets with feed-grade amino acids and proving the economic benefits of their additions. To date, widespread adoption of feed-grade amino acids is limited to methionine, lysine, threonine, and to some extent valine. With valine and isoleucine gaining prevalence in commercial formulation, classic data on the antagonisms associated with the branched-chain amino acids has returned to the forefront of practical broiler nutrition research. Therefore, a series of 23 …

Directed Genome Evolution To Identify Genes For Macrophage Survival By Staphylococcus Agnetis, Sonali Lakshika Anne Lenaduwe Lokuge

Graduate Theses and Dissertations

Bacterial Chondronecrosis with Osteomyelitis (BCO) is a debilitating infection that negatively impacts animal welfare and costs the broiler industry billions of dollars annually. We have previously isolated Staphylococcus agnetis 908 from BCO samples obtained from broilers at the University of Arkansas research farm. This isolate can induce BCO lameness at greater than 50% in broilers exposed to the pathogen in drinking water. We found that S. agnetis 908 is capable of surviving and escaping macrophages compared to a closely related cattle isolate,1379. Through Directed Genome Evolution (DGE) we identified that this difference is at least partially associated with an alanine …

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 …

Evaluation Of Weight Gain, Feed Intake, Feed Conversion And Oocyst Shedding Of Eimeria Maxima And Eimeria Acervulina In Broiler Chickens, Lauren Laverty

Poultry Science Undergraduate Honors Theses

The purpose of the present study was to evaluate the day and the time of sample collection of an

experimental challenge with Eimeria maxima (EM) and Eimeria acervulina (EA) in broiler chickens. One day old male Cobb-Vantress broiler chickens were randomly allocated to one of three groups with ten replicates (n=8 chickens/replicate). Chickens were placed in battery cages with a controlled age-appropriate environment: Group 1) Negative control (no challenge or treatment); 2) Challenge control (Eimeria challenge only); 3) Challenge + Salinomycin. Challenged chickens were orally gavaged with the mixed culture of EM/EA (10,000 sporulated EM containing 4% wild-type EA) …

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 …

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%. …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Optimizing Animal Welfare In Commercial Laying Hens Through Novel Management Practices And Farm Manager Evaluation, John R. Brunnquell

Theses and Dissertations--Animal and Food Sciences

The commercial production of pasture and free-range eggs in the United States is expanding rapidly. According to the United States Department of Agriculture Agricultural Management Assistance, in May of 2019 there were 2.6M pasture hens and 4.5M free-range hens representing 1.9% of the nation’s laying flock. There is little industry and/or academic experience with this style of production in the United States. Programs such as the European Layer Training Initiative (ELTI), which emerged in 2019, have tried to fill this void but participation from the US was low. The principal sources for guidance of commercial free-range egg production in the …

The Impacts Of Administering Metabolites Of Saccharomyces Cerevisiae On Broiler Performance, Yields And Salmonella Content Of Component Portions, Bill Douglas Potter

Graduate Theses and Dissertations

The impacts of using health-promoting Saccharomyces cerevisiae fermentation metabolites in poultry production and processing can be measured in respect to multiple measures of success. Traditionally this yeast-based compound has been administered to poultry, livestock, poultry, and other species to improve animal performance and production volume output. In addition, Saccharomyces cerevisiae fermentation metabolites have also been shown in more recent research to reduce colonization of pathogenic bacteria in the host organism’s gastro-intestinal tract. In this dissertation, the impacts of administering a functional ingredient containing Saccharomyces cerevisiae metabolites on broiler performance measures and pathogen reduction were measured. One of the studies in …

Study Of Three Potential Variables That May Impact The Maximum Shear Force And Shear Variation During The Growth And Transport Of Mixed Sex Broilers Grown In Commercial Poultry Houses, Mark Christie

Graduate Theses and Dissertations

Temperature conditions during the transportation to the processing facility of commercial broilers have a direct impact on the meat texture, specifically maximum shear force and shear variation of cooked breast meat. Analysis of a calendar year of flock data (N=346), reveals that the largest impact of transport conditions, specifically temperature, is on the standard deviation of the flocks range of cooked shear values. The optimal transport temperature that yields broiler breast meat with average flock minimum shear and standard deviation values is approximately 60°F. The shear values for flocks at or near 60°F are on average 1 kg less than …