Life Sciences Commons^™

Applying A One Health Approach To Expand Disease Surveillance In Eastern Wildlife, Eliza L. Baker

Doctoral Dissertations

Urban wildlife carry numerous diseases of veterinary and human health importance. Many of these diseases are emerging into new geographic areas, including the southeastern United States, due to a combination of climate change, urbanization, and migration. Urban wildlife can act as excellent sentinels for these diseases, providing doctors and veterinarians with a better understanding of the risks to their patients. We sought to better understand a variety of diseases of human and animal concern via urban wildlife surveillance. We found a high prevalence of numerous zoonotic and companion animal diseases in wildlife, both with and without significant health impacts on …

Investigating The Cellular Foundations Of Breast Muscle Myopathies In Broiler Chickens, Usuk Jung

Doctoral Dissertations

The genetic selection for high growth rate, breast muscle yield, and feed efficiency in modern broilers has been a double-edged sword. While it has resulted in the desired traits, it has also led to broiler myopathies. Recent omics studies have shown that hypoxia may be a potential factor that damages the myofiber niche and compromises muscle repair processes. The objective of this study was to optimize isolation protocols for primary broiler satellite cells (SCs) and fibroadipogenic progenitors (FAPs) and to characterize SCs proliferation and differentiation under hypoxia. The study first focused on the optimization of isolation procedures and culture conditions …

Evaluation Of Treatment Options And Investigation Of Pathogenesis Of Chytridiomycosis In North American Salamanders, Anastasia Elaine Towe

Doctoral Dissertations

Chytridiomycosis, a cutaneous fungal disease caused by two related fungi, Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), is a major cause of amphibian population declines worldwide. Bd has a broad distribution, covering every continent except for Antarctica. Meanwhile, Bsal is currently restricted to Europe and Asia. Treatment options for both Bd and Bsal remain a major area of concern for wild populations. Recently, implants for long-term, parenteral antifungal drug administration have shown some promise in fungal diseases in wildlife. We investigated the safety and efficacy of an intracoelomic implant of the antifungal drug terbinafine in greater …

Airborne Transmission Of Pathogens Emerging In The Poultry Industry, Xuan Dung Nguyen

Doctoral Dissertations

Poultry houses might have high levels of airborne pathogens, including Escherichia coli (E. coli) and avian influenza (AI), which may be transmitted through the air and pose risks of infection. The objective of the dissertation is to provide an insightful understanding the of airborne transmission of E. coli and AI which were attached to poultry dust particles.

Chapter I and VI summarized background, gap in knowledge, and discussed the limitations and implications of the study.

Chapter II compared the efficiency of Andersen six-stage impactor, all-glass impinger, and ACD-200 Bobcat, in collecting airborne E. coli carried by dust particles. The results …

Corn (Zea Mays L.) Production In Living Mulch Systems, Grazing Potential, And Economic Viability, Marcia Peireira Quinby

Doctoral Dissertations

Living mulch (LM) is a practice in which forages are grown simultaneously with the main crop, serving as a living cover throughout the growing season. The LM systems were developed to alleviate concerns of soil depletion and finding ways to reduce tillage negative effects on soil productivity. In addition, when legumes are use can decrease the reliance on N fertilizer. The use of corn in LM have been previously studied due to the crop being a large commodity in the U.S.; In addition, the ability to graze the LM after corn production can increase the land use efficiency. To determine …

Cerulean Warbler Full Annual Cycle Ecology: Filling In Critical Knowledge Gaps, Douglas W. Raybuck

Doctoral Dissertations

Cerulean Warblers (Setophaga cerulea) are a declining migratory bird species of conservation concern that breed in mature hardwood forests of eastern North America and spend the stationary non-breeding period in the tropical Andes of South America. To reverse their >50-year population decline, a full annual cycle conservation strategy is needed. However, several important knowledge gaps have limited our understanding of this species’ full annual cycle ecology, including migration ecology, response to forest management on the breeding grounds, and basic ecology during the stationary non-breeding period in Andean forests. From geolocator data, we found a moderate pattern of migratory …

The Effects Of Urbanization On The Avian Gut Microbiome, Mae Berlow

Doctoral Dissertations

The gut microbiome influences and is influenced by the host, and can affect the host organism by contributing to health, development and immunity. Similarly, the host can influence this community; it’s makeup can vary with host species, locality, diet, social stressors, and environmental stressors. Some of these environmental stressors have arisen due to human-induced rapid environmental change, like urbanization. The physiology and behaviors of organisms that are able to persist in urban environments are often different from their non-urban congeners. Nutrition, development, and immunity—all of which are affected by the gut microbiome—are important factors that can determine survival in urban …

Microbial And Metabolomic Biomarkers Of Feed Efficiency In Angus Cattle, Brooke Ashley Clemmons

Doctoral Dissertations

In Tennessee and the United States, cattle account for a significant proportion of the livestock agricultural sector. In the beef cattle industry, 40-70% of the total cost of production comes from feed costs, resulting in billions of dollars going towards feeding cattle. Thus, identifying methods for improving feed efficiency is imperative for reduced feed input costs and more effective use of environmental and economic resources. The rumen microbiome contributes a vast amount of nutrients for the host ruminant, including approximately 70% of energy precursors as well as vitamins, proteins, and other nutrients. These microbes produce metabolites that are then available …

Identifying Genome Associations With Unique Mastitis Phenotypes In Response To Intramammary Streptococcus Uberis Challenge, Lydia Jean Siebert

Doctoral Dissertations

Mastitis, the inflammation of the mammary gland, dramatically decreases dairy industry revenues and milk quality, making improved control and prevention methods a goal of the industry. Prior research has observed variation in response to experimental challenge with regards to inflammation indicators, S. uberis concentrations, and the need for antibiotics. To determine possible causes of the observed variation following experimental S. uberis intramammary challenge, we performed genome association analyses (N = 34 – 36 Holstein dairy cows), a linkage analysis, and S. uberis milk inoculation (N = 21 Holstein dairy cows) trials. Association analyses were done using Illumina’s BovineSNP50 BeadChip and …

Alternative Approaches To Improving The Welfare Of Transition Dairy Cows And Their Calves: Use Of Exercise, Randi Alyson Black

Doctoral Dissertations

Transition cows are the cows most susceptible to disease and prevalence has not changed over the past decade. However, increased physical activity during late gestation may represent a management option to improve transition. Therefore, the objectives of this study were to determine the effect of exercise, pasture turnout, or total confinement on 1.) physical fitness and cortisol concentrations during the dry period, 2.) neutrophil function and behavior during the dry period, 3.) horn growth and wear and sole thickness during the dry period 4.) calving behavior and cortisol concentrations at parturition, and 5.) calf performance, behavior, and cortisol concentrations at …

Health Assessment Of Two Reintroduced Populations Of American Martens (Martes Americana) In Michigan, Maria Catherine Spriggs

Doctoral Dissertations

The American marten (Martes americana) was extirpated from Michigan during the early-20th century due to loss of vast areas of mature conifer forest and unregulated trapping. The species was reintroduced into the Upper Peninsula (UP) and Northern Lower Peninsula (NLP) during the mid-20th century. While the American marten population in the UP has grown and is doing well, the population in the NLP has been less successful. The reasons for the limited success of the NLP population are unknown, but may include lack of suitable habitat, limited reproductive success, poor genetic diversity, disease, or negative environmental impacts. American …

Evaluation Of Reproductive Efficiency In Lactating Dairy Cows Through Physiologic Evaluation And Synchronization Modification, Charles Dexter Young

Doctoral Dissertations

Reproductive performance of lactating dairy cows has decreased as milk production has increased as a result of genetic selection. Milk production alone is not the reason for decreased reproductive performance, as fertility issues are multifactorial and collaborative. Research chapters contained within have taken an applied approach focusing in two different areas of fertility. One approach was development of an evaluation system to identify lactating cows with decreased fertility prior to breeding; while another approach was to modify an ovulation synchronization protocol during periods of heat stress in order to improve fertility. The first focus was development and evaluation of a …

Thermal Inactivation Of Shiga Toxin-Producing Escherichia Coli In Foods, Malcond David Valladares

Doctoral Dissertations

Emerging non-O157 Shiga toxin-producing Escherichia coli (STEC) were recently added to the zero tolerance policy by the USDA-FSIS. Therefore, the precise characterization of their thermal inactivation kinetics in different foods and the effect of stress on thermal inactivation are needed. This research aimed at determining the heat inactivation kinetics of non-O157 and O157 STECs in buffer and model food matrices and the effects of DnaK levels on thermal resistance after acid and heat-shock. Thermal inactivation was carried out in either in 2-ml glass vials or nylon vacuum-sealed bags for buffer and food (spinach, ground-beef, turkey deli-meat, pasta) samples, respectively. Vials …

Absorption And Utilization Of Choline And Vitamin B12 In Lactating Dairy Cows Using Different Delivery Methods, Virginia Maria Artegoitia Etcheverry

Doctoral Dissertations

Choline and vitamin B12 are essential nutrients for growth and performances of production animals. However, both nutrients are extensively degraded during digestion in the rumen. This thesis comprised three experiments. First, four cows equipped with a rumen cannula and catheters in the portal vein and a mesenteric artery received a post-ruminal bolus of: 1) cyanocobalamin (CN-CBL) alone (0.1 g) [gram], 2) CN-CBL (0.1 g) + casein (10 g) or 3) CN-CBL (0.1 g) + whey proteins (10 g). After the bolus, blood samples were taken until 24 h [hour] post-bolus. The intestinal absorption of CN-CBL was greater when the vitamin …

Casein Micelles And Their Properties: Polydispersity, Association With Vitamin A And Effect Of Ultra-High Pressure Homogenization, Maneesha Sheenu Mohan

Doctoral Dissertations

The internal structure of casein micelles is not fully understood. In the present work, we explore some of the basic questions about casein micelles in bovine milk including its size distribution, native binding properties and effect of ultra-high pressure homogenization (ultra-HPH) on technological properties of casein micelles. The size distribution of casein micelles was studied by cryo-TEM using skim milk from four cows. The degree of variation in casein micelle sizes (polydispersity) ranged between 0.39 and 0.47 for a size distribution ranging from 10 to 693 nm. These results indicated high polydispersity of casein micelles in milk from single cows. …

Regional Assessment Of The Relationships Of Conservation Practices To Northern Bobwhite And Other Priority Grassland Bird Breeding Populations, Christopher Manuel Lituma

Doctoral Dissertations

I documented populations of Northern Bobwhites (Colinus virginianus) and other priority grassland and early successional birds in the Central Hardwoods Bird Conservation Region (CHBCR), and determined whether conservation practices have been effective in positively impacting species occupancy and abundance. I designed and implemented a roadside survey by randomly locating five 15-km routes with 5-min unlimited distance point counts (30 counts/route), along secondary roads within Northern Bobwhite focal counties (n = 37) in the CHBCR. I also developed a survey to assess roadside biases for estimates of relative abundance (a), occupancy (ψ), detection probability (p), and associated …

Evolution Of Acquiescence To Manipulation, Mauricio González-Forero

Doctoral Dissertations

A productive framework to study phenotypic evolution is based on the notion of ``inclusive fitness'', which considers how an individual's phenotype affects the fitness of other individuals. A promising extension of the notion of inclusive fitness is that of the ``extended phenotype'', which considers how an individual's phenotype affects its environment, including the phenotype of other individuals. Affecting another individual's phenotype is sometimes referred to as manipulation (which introduces indirect genetic effects). However, manipulated individuals may evolve resistance to manipulation, possibly reducing or eliminating the manipulated behavior (and the indirect genetic effects). In this dissertation I use mathematical modeling to …

Isolation, Antibiotic Resistance, And Molecular Characterization Of Campylobacter From Poultry, Swine And Dairy Cows, Willie James Taylor

Doctoral Dissertations

This study was conducted to determine presence, antibiotic resistance, and genetic relatedness of Campylobacter on diverse farm types. Cloacal fecal samples from poultry (broilers, layers, and turkey breeders), and fecal rectal samples from non-poultry animals (farrowing sows, finisher pigs, and lactating dairy cows) were tested for Campylobacter using BAM protocols. Agar disk diffusion method was used to determine antibiotic resistance, and PFGE analysis to determine genetic relatedness of isolates recovered within the different farm types. Campylobacter was detected in 34.8% (range of 6.7 to 62.0%, P < 0.001) of cloacal samples from poultry, in 61.4% (range of 55.0 to 69.0%, P < 0.05), and 26.0% (range of 19.0 to 34.0%, P < 0.05) of rectal samples from pigs, and dairy cows, respectively. Antibiotic resistance was detected in 30.2% (range of 0 to 82.4%, P …

Improving Beef Cattle Performance On Tall Fescue, Brian Thomas Campbell

Doctoral Dissertations

The overall goal of the studies described in this dissertation was to improve beef production of cows grazing endophyte infected tall fescue either through management practices or through identifying markers for genetic selection. Experiment 1 investigated differences in spring and fall calving herds grazing endophyte infected tall fescue. This study determined that managing for a fall calving beef herd is the more productive and efficient system. This is due to increased reproductive efficiency as well as traditionally greater market prices at the time of weaning. A spring calving system will have faster growing calves, but the increased weight of the …

The Small Indian Mongoose (Herpestes Auropunctatus) On Adriatic Islands: Impact, Evolution, And Control, Arijana Barun

Doctoral Dissertations

ABSTRACT

One cause of declines and extinctions of island species is carnivore introduction. Four carnivores, including the small Indian mongoose (Herpestes auropunctatus), are on the IUCN’s list of 100 of the World's Worst Invasive Alien Species. My thesis summarizes global patterns of carnivore introductions and examines ecological, evolutionary, and management impacts of this mongoose. I study abundances of reptiles and amphibians on mongoose-infested and mongoose-free islands in the Adriatic Sea to determine if factors other than mongoose presence can account for abundance differences. For several reptiles and amphibians, the mongoose is implicated as causing differences. Additionally, I …

Diagnosis And Management Of Horses With Equine Metabolic Syndrome (Ems), Kelly Ann Chameroy

Doctoral Dissertations

In horses, a painful and often debilitating disease known as laminitis can result in impaired function and, in severe cases, euthanasia. Equine Metabolic Syndrome (EMS) is a syndrome in horses that results in development of laminitis and is characterized by the presence of general and/or regional adiposity (“cresty neck”), aberrations in blood lipid concentrations, insulin resistance (IR) and/ or hyperinsulinemia. Therapies have focused on improving the state of obesity and insulin resistance with the goal of diminishing the likelihood of laminitis development. A definitive cause for laminitis has not been established, but hyperinsulinemia and IR are likely candidates as experimental …

“Development Of Genetic And Genomic Predictors Of Fertility In Argentinean Holstein Cattle.”, Fernando Alfonso Di Croce

Doctoral Dissertations

The overall aim of the studies described herein was to evaluate genetic variation in cattle fertility traits for development of genetic and genomic predictors in breeding strategies. Results from these experiments suggest that improvements in fertility through genetic selection are a possible approach to increase reproductive efficiency. Experiment 1 evaluated the development of genetic parameters associated with multiple ovulation and embryo transfer schemes in an attempt to assist producers in identifying animals with greater genetic merit for these protocols. This study confirmed that genetic selection of donors or sires appears to be a potential approach to improve efficiency of MOET …

Identifying Mechanisms Associated With Innate Immunity In Cows Genetically Susceptible To Mastitis, Alexandra Alida Elliott

Doctoral Dissertations

Mastitis, or mammary gland inflammation, causes the greatest loss in profit for dairy producers. Mastitis susceptibility differs among cows due to environmental, physiological, and genetic factors. Prior research identified a genetic marker in a chemokine receptor, CXCR1, associated with mastitis susceptibility and decreased neutrophil migration. Current research seeks to identify reasons behind mastitis susceptibility by validating this model through in vivo challenge with Streptococcus uberis and studying specific mechanisms causing impaired neutrophil migration. Holstein cows with GG (n=19), GC (n=28), and CC (n=20) genotypes at CXCR1+777 were challenged intramammarily with S. uberis strain UT888. After challenge 68% of quarters from …

Direct Effects Of Heat Stress During Meiotic Maturation On Bovine Oocyte And Cumulus Rna, Rebecca R. Payton

Doctoral Dissertations

Heat-induced reductions in developmental competence after direct exposure of oocytes to 41ºC have been coincident with reduced protein synthesis. Since heat stress perturbs RNA integrity and polyadenylation in somatic cells, it was hypothesized that heat stress during meiotic maturation may alter RNA within oocytes and/or their surrounding cumulus to account for some of the reductions in development. Initial efforts utilized microcapillary electrophoresis to examine oocyte and cumulus RNA without heat stress as a first step toward transcriptome profile analysis. Size distribution of RNA, rRNA ratio, and other related endpoints differed for oocyte RNA compared to cumulus, and were conserved across …

Spermatogonia Stem Cell Dynamics Following Hormonal Induction, Ischemic Disturbance In Vivo Or Proliferation Under In Vitro Culture In Pre- And Postpubertal Bulls, Gustavo M. Schuenemann

Doctoral Dissertations

The overall aim of the studies described herein was to evaluate bovine spermatogonial cell dynamics under various conditions. Results from these experiments will provide the basis for potential production of offspring following spermatogonial stem cell transfer. Experiment 1 evaluated gonadotropin administration effects at initiation of inhibin passive immunization in Jersey bull calves on testicular morphology and development. Primary treatments consisted of control (KLH) or immunization (INH) plus a combination of saline, FSH, or GnRH. Administration of FSH at the time of initial immunization against inhibin significantly increased number of germ cells (92.2 ± 9 x 106 cells) compared to INH-Saline …

Prevalence Of Class 1 Integrons And Antibiotic Resistance Patterns In Bacteria Of Swine And Chicken In The Us And Thailand, Sumalee Liamthong

Doctoral Dissertations

Studies were conducted to investigate the prevalence and potential for transfer of class 1 integrons and antimicrobial resistance in bacteria of broiler chickens and swine from the US and Thailand. Antibiograms were characterized and integron sequences were detected using standard methods. To determine if transfer of integrons occurred between bacterial species the location of the integrons (plasmid versus chromosome) was determined, and when integron-positive E. coli and Salmonella isolates possessed identical amplicon patterns, PCR products were sequenced to determine homology. Class 1 integrons were detected in 1,732 of 3,824 isolates from broiler chickens and 1,782 of 4,253 isolates from swine. …

Feline Lentivirus: Molecular Analysis And Epidemiology In Southern African Lions, Hayley Rebecca Adams

Doctoral Dissertations

Feline immunodeficiency virus is a retrovirus of domestic cats causing significant lifelong infection. Infection has also been detected in nondomestic species, including African lions. It is endemic in certain populations in east and southern Africa. Infection leads to immunologic dysfunction and immunosuppressive disease in domestic cats; however, little research exists about the pathogenic effects of infection in lions and its epidemiological impact on free-ranging and captive populations. Little is known about the lentivirus in these populations at the molecular and host level. Analysis of the virus from these populations is necessary for development of detection assays that are both sensitive …

An Experimental Release Of Elk Into Great Smoky Mountains National Park, Jennifer Lynn Murrow

Doctoral Dissertations

I conducted 6 years of field work to evaluate the habitat use and population dynamics of an experimental release of elk (Cervus elaphus) into Great Smoky Mountains National Park (Park). Elk exhibited relatively small home ranges (female: 10.4 km² and males: 22.4 km²) and movement distances decreased over time. I calculated survival rates (x = 0.73–0.93) and litter production rates (x = 0.73) for the population. To assess the potential for a long-term elk population, I incorporated those vital rates into the population modeling software Riskman and tested its sensitivity to any given …

Effects Of Egg Yolk Antibodies On Weanling Pigs Challenged With Pathogenic Salmonella Typhimurium, Sukanya Rattanatabtimtong

Doctoral Dissertations

An experiment was conducted to determine effects of anti-Salmonella egg yolk antibodies (ASEYA) on shedding and antibiotic resistance of Salmonella enterica Typhimurium and E. coli, growth performance and immunological parameters. Weaned pigs in two replicate trials (n = 132) were randomly assigned to six dietary treatments, including a control diet without additives, apramycin followed by carbadox, oxytetracycline (OXY), egg yolk powder containing ASEYA, egg yolk powder lacking ASEYA, or spray dried plasma protein (SDPP). Treatments were given to pigs on day 3 of the trial and all pigs were intranasally and orally challenged with Salmonella Typhimurium containing a …

Inhibition Of Direct Prostaglandin F2Α Effects On Pre-Attachment Embryos Improves Reproductive Efficiency In Cattle, Fernando Nestor Scenna

Doctoral Dissertations

Prostaglandin F_2α (PGF_2α) has been shown to have detrimental effects on embryonic development, quality and hatching ability of embryos and pregnancy rates in cows. However, information about PGF_2α receptor (FPr) mRNA and protein in the preattachment bovine embryo is absent in the literature. The first experiment was design to identify the period of time during in vitro embryo development that is most susceptible to PGF_2α and to determine FPr mRNA and protein in bovine embryos. Prostaglandin F_2α decreased development of embryos to compact morula, but had no effect on development to blastocyst. In addition, …