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Articles 1 - 30 of 149

Full-Text Articles in Animal Diseases

Testing The In Vitro Effectiveness Of Protease Inhibitors Against Histomonas Meleagridis, Evy Belle Hafer May 2026

Testing The In Vitro Effectiveness Of Protease Inhibitors Against Histomonas Meleagridis, Evy Belle Hafer

Animal Science Undergraduate Honors Theses

Histomonas meleagridis is a protozoal parasite able to exist in a flagellated or amoeboid form that infects gallinaceous birds, particularly turkeys, and causes significant mortality. There is currently no effective treatment for this disease. The purpose of this study was to assess the anti-histomonal activity of commercially available protease inhibitors, leupeptin, bestatin, and antipain, using an established in vitro model. Three protease inhibitors, leupeptin, bestatin, and antipain, were evaluated across five assays. Treatment groups included: 1) non-treated control, 2) leupeptin 100 µM, 3) bestatin hydrochloride 100 µM, and 4) antipain dihydrochloride 100 µM. Histomonads were enumerated using a hemocytometer after …


Investigating The Influence Of Dietary Phytogenics And Postbiotics On Horizontal Transmission Of Histomonas Meleagridis In Commercial Turkey Poult Hens, Diego Fernando Cortes Velez May 2026

Investigating The Influence Of Dietary Phytogenics And Postbiotics On Horizontal Transmission Of Histomonas Meleagridis In Commercial Turkey Poult Hens, Diego Fernando Cortes Velez

Graduate Theses and Dissertations

Histomonas meleagridis is a parabasalid protozoan and the causative agent of histomonosis, or blackhead disease, in turkeys. Withdrawal of the last remaining in-feed arsenical from the market in 2015 led to the re-emergence of the disease. As a result, there is a need to investigate alternatives, such as dietary inclusion of postbiotic and phytogenic compounds, to reduce H. meleagridis transmission and disease severity in commercial turkey flocks. The purpose of this project was to evaluate the influence of dietary inclusion of three different combinations of postbiotic and phytogenic compounds on H. meleagridis transmission in turkey poult hens. A thesis introduction …


In Vitro And In Vivo Evaluation Of The Effect Of A Commercial-Dried Enterococcus Faecium Fermentation Product As Quorum Sensing Inhibitors Of Salmonella Enterica Typhimurium, Ileana Loeza May 2025

In Vitro And In Vivo Evaluation Of The Effect Of A Commercial-Dried Enterococcus Faecium Fermentation Product As Quorum Sensing Inhibitors Of Salmonella Enterica Typhimurium, Ileana Loeza

Graduate Theses and Dissertations

The purpose of the present research was to evaluate Enterococcus faecium fermentation peptides (EFP) for antibacterial activity, inhibition of biofilm formation, and anti-quorum sensing properties against Salmonella Typhimurium (ST) in in vitro trials and individual body weight and ST organ colonization in therapeutic and prophylactic models in broiler chickens. Ninety-six day-of-hatch Cobb 500 broiler chickens were randomized and assigned to one of four treatments: NC) Negative Control, no EFP treatment and no ST challenge; NC+EFP) Negative Control, EFP treatment and no ST; PC) Positive Control, no EFP treatment and ST challenge, and PC+EFP) EFP treated and ST challenged. Independent trials …


The Inclusion Of Soybean Co-Products In Ruminant Supplements On Health And Reproductive Efficiency, Kirsten Midkiff Dec 2024

The Inclusion Of Soybean Co-Products In Ruminant Supplements On Health And Reproductive Efficiency, Kirsten Midkiff

Graduate Theses and Dissertations

Soybeans are a vital commodity for Arkansas and the United States, with co-products such as soybean meal having wide popularity in animal feeds due to high protein content and palatability. Soybean meal primarily is utilized in diets for swine and poultry operations with a small market in the beef cattle industry, likely due to the increased costs that are associated with the product. On the other hand, soybean oil is a product from the production of soybean meal that is not as widely used in the livestock industry as most of the oil produced is used for industrial purposes. Additionally, …


Intervention Measures Alleviating Bacterial Chondronecrosis With Osteomyelitis In Broilers: Experimental Lameness And Feed Additive Treatments, Andi Asnayanti May 2024

Intervention Measures Alleviating Bacterial Chondronecrosis With Osteomyelitis In Broilers: Experimental Lameness And Feed Additive Treatments, Andi Asnayanti

Graduate Theses and Dissertations

As the global population grows, the supply and demand for meat have dramatically increased. The poultry industry has managed to satisfy the high demand for chicken meat through fast-growing broilers. The poultry breeder industry has successfully provided modern broilers with high liveability, feed efficiency, and processing yields through genetic selection of the traits of interest such as growth rate, feed conversion rate, and breast quality. Nevertheless, the intensive selection of modern broiler chickens for fast growth and feed efficiency leads to unintended side effects, such as excessive fat, low reproductive performance, leg abnormalities, low immunity, cardiovascular diseases, and metabolic disorders. …


Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson Dec 2023

Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson

Graduate Theses and Dissertations

Bats are an ecologically important taxon that can host zoonotic pathogens. Globally, many bat species are synanthropic and live closely with humans, often roosting in man-made structures. The spatial overlap between humans and bats creates opportunities for human-bat contact, which can lead to human exposure to bat-borne pathogens and conflicts that cause bat mortality. Despite this risk, little is known about the drivers and characteristics of these human-bat interactions in buildings and work is needed to understand this aspect of the wildlife-urban interface. In Chapter I, I present a literature review that identifies the geographic and taxonomic trends in reported …


Evaluation Of The Effect Of Enterococcus Cecorum Exposure During Late Embryogenesis On Systemic Disease And Early Performance In Broiler Chickens, Marcela Arango May 2023

Evaluation Of The Effect Of Enterococcus Cecorum Exposure During Late Embryogenesis On Systemic Disease And Early Performance In Broiler Chickens, Marcela Arango

Graduate Theses and Dissertations

The objective of this thesis was to investigate the effects of Enterococcus cecorum (EC) administration into the amnion at day 18 of embryogenesis on performance and septicemia development in broiler chickens. Chapter I consists of a brief overview of the thesis. Chapter II provides a literature review on EC-related disease in broiler chickens and methods to isolate, detect, and differentiate between commensal and pathogenic strains of EC. Chapter III consists of a study conducted to determine if different EC strains isolated from field cases that exhibited septicemia and high mortality impacted hatchability, livability, organ colonization, and early performance in broiler …


An Ecological Perspective Of American Rodent-Borne Orthohantavirus Surveillance, Nathaniel Mull May 2023

An Ecological Perspective Of American Rodent-Borne Orthohantavirus Surveillance, Nathaniel Mull

Graduate Theses and Dissertations

Orthohantaviruses are a global group of viruses found primarily in rodents, though several viruses have also been found in shrews and moles. Many rodent-borne orthohantaviruses are capable of causing one of several diseases in humans, and the mortality associated with these diseases ranges from < 0.1% - 50% depending on the specific etiological virus. In North and South America, orthohantavirus research was ignited by an outbreak of severe disease in the Four Corners region of the United States in 1993. However, despite the discovery of over 20 orthohantaviruses in the Americas, our understanding of orthohantavirus ecology and virus-host dynamics in this region is still limited, and orthohantavirus surveillance is generally restricted in scope to select regions and small portions of host distributional ranges. In Chapter I, I present a literature review on the current understanding of American rodent-borne orthohantavirus ecology. This review focused on under-studied orthohantaviruses, addressing gaps in knowledge by extrapolating information from well-studied orthohantaviruses, general rodent ecology, and occassionally from Eurasian orthohantavirus-host ecology. There were several key conclusions generated from this review that warrant further research: 1) the large number of putative orthohantaviruses and gaps in orthohantavirus evolution necessitate further surveillance and characterization, 2) orthohantavirus traits differ and are more generalizable based on host taxonomy rather than geography, and 3) orthohantavirus host species are disproportionately found in grasslands and disturbed habitats. In Chapter II, I present a prioritized list of rodent species to target for orthohantavirus surveillance based on predictive modeling using machine learning. Probable orthohantavirus hosts were predicted based on traits of known orthohantavirus hosts using two different types of evidence: RT-PCR and virus isolation. Predicted host distributions were also mapped to identify geographic hotspots to spatially guide future surveillance efforts. In Chapter III, I present a framework for understanding and predicting orthohantavirus traits based on reservoir host phylogeny, as opposed to the traditional geographic dichotomy used to group orthohantaviruses. This framework establishes three distinct orthohantavirus groups: murid-borne orthohantaviruses, arvicoline-borne orthohantaviruses, and non-arvicoline cricetid-borne orthohantaviruses, which differ in several key traits, including the human disease they cause, transmission routes, and virus-host fidelity. In Chapter IV, I compare rodent communities and orthohantavirus prevalence among grassland management regimes. Sites that were periodically burned had high rodent diversity and a high proportion of grassland species. However, rodent seroprevalence for orthohantavirus was also highest in burned sites, representing a trade-off in habitat management outcomes. The high seroprevalence in burned sites is likely due to the robust populations supported by the high quality habitat resulting from prescribed burning. In Chapters V and VI, I describe Ozark virus and Sager Creek virus, two novel orthohantaviruses discovered from specimens collected during Chapter IV. Both chapters report full genome sequences of the respective viruses and compare both nucleotide and protein phylogenies with related orthohantaviruses. Additionally in Chapter VI, I support the genetic analyses with molecular and ecological characterizations, including seasonal fluctuations in host abundance, correlates of prevalence, evidence of virus shedding, and information on host cell susceptibility to Sager Creek virus.


Identification Of Possible Vectors For Histomoniasis In Turkeys On Commercial Farms In Arkansas And Oklahoma, Treva Dillon Dec 2022

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 …


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 Dec 2022

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 …


The Role Of Microbiota-Biotransformed Bile Acid Metabolites On Campylobacter Jejuni- And Clostridium Perfringens-Infection, Ying Fu Dec 2022

The Role Of Microbiota-Biotransformed Bile Acid Metabolites On Campylobacter Jejuni- And Clostridium Perfringens-Infection, Ying Fu

Graduate Theses and Dissertations

Campylobacter jejuni (C. jejuni) and Clostridium perfringens (C. perfringens) are two leading pathogenic bacteria responsible for both human and animal diseases. In chapters Ⅱ to Ⅳ, I presented an overview of current knowledge on the role of immune response, microbiota, bile acids and their microbial metabolites on campylobacteriosis, and C. perfringens induced necrotic diseases.In chapter Ⅴ, I investigated effects of deoxycholic acid-modulated anaerobes (DCA-Anaero) on attenuating chicken transmission-exacerbated campylobacteriosis. SPF Il10-/- mice were gavaged with clindamycin for 7 days followed by infected with three C. jejuni strains, Cj-P0 (C. jejuni AR101), Cj-P1 (from chicken pre-infected with C. jejuni AR101), and …


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 Dec 2022

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 …


Histomonosis In Turkeys – Factors Influencing Transmission, Pathogenesis, And The Search For Prophylactic Or Therapeutic Compounds, Thainá Landim De Barros Aug 2022

Histomonosis In Turkeys – Factors Influencing Transmission, Pathogenesis, And The Search For Prophylactic Or Therapeutic Compounds, Thainá Landim De Barros

Graduate Theses and Dissertations

The incidence of histomonosis has been increasing in poultry since the ban of prophylactic and therapeutic compounds. Histomonosis is caused by the protozoa Histomonas meleagridis. The objective of this dissertation was to investigate factors impacting the pathogenesis and transmission of histomonosis and to evaluate compounds that could potentially prevent or reduce the severity of histomonosis in turkeys. In the first study, the effect of sodium chlorate and sodium nitrate on reducing histomonads growth was tested in vitro and added to a basal turkey diet. A decrease in the growth of histomonads in vitro was observed, but no in vivo effect …


Intestinal Microbiota Analysis Of Broiler Chickens Under Necrotic Enteritis Challenge And Tributyrin Supplementation, Taylor Nicole Mckinney Aug 2022

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 …


Evaluation Of The Effect Of A Lippia Organoides Essential Oil Extract On Clostridium Perfringens Proliferation In Vitro And Necrotic Enteritis In Broiler Chickens, Makenly E. Coles May 2022

Evaluation Of The Effect Of A Lippia Organoides Essential Oil Extract On Clostridium Perfringens Proliferation In Vitro And Necrotic Enteritis In Broiler Chickens, Makenly E. Coles

Graduate Theses and Dissertations

The purpose of the present research was to assess the effects of essential oils derived from the plant Lippia organoides on performance parameters, intestinal integrity, and necrotic enteritis (NE) in broiler chickens. To do this, a previously established challenge model for NE was utilized which included challenging with Salmonella Typhimurium on day 0, Eimeria maxima on day 18, and Clostridium perfringens on days 22 and 23. Treatment groups included a 1) non-challenged, negative control, 2) challenged control, and 3) challenged, Lippia origanoides (37ppm in the diet). Group 1 (negative control) had significantly (P < 0.05) higher body weight gain from d8-25 and d0-25 compared to both challenged groups. Feed intake was significantly different for all three groups (P < 0.05) at 8-25 days and 0-25 days with group 1 having the highest feed intake for both time periods. Total mortality was greater in the positive control when compared to both the negative and treatment groups. NE lesion scores were significantly different between all groups with the positive control having the highest mean lesion scores and the negative control having a mean lesion score of 0. The positive control group had the highest FITC-d amounts detected in the sera, being statistically higher than both the treatment group and negative group which were both statistically different from each other. At the present inclusion rate for the essential oil (37 ppm), there was an overall reduction in the negative impact from the NE infection. Further studies should be conducted to reach more significant conclusions.


Investigating Molecular Mechanisms Behind Bacterial Chondronecrosis With Osteomyelitis (Bco) Pathogenesis In Modern Broilers, Alison Ramser May 2022

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 …


Monkeypox Virus Hosts And Transmission Routes: A Systematic Review Of A Zoonotic Pathogen, Mary Walker May 2022

Monkeypox Virus Hosts And Transmission Routes: A Systematic Review Of A Zoonotic Pathogen, Mary Walker

Biological Sciences Undergraduate Honors Theses

Monkeypox virus (MPXV) is an etiological agent of Monkeypox with origins believed to be of Central/West Africa. As a member of the orthopoxvirus family and due to its increasing emergence, it has become a pathogen in need of research. This paper works to find common trends of transmission routes and reservoir hosts in previous publications through a systematic review. Articles found on Web of Science containing the search term “Monkeypox” were sorted based on relevance to the review topics of potential reservoir hosts and transmission routes of Monkeypox virus. Through Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 1,036 …


Evaluation Of Two Neonatal Challenge Models For Broiler Chickens And Their Effects On Early Performance Parameters, Callie Selby Dec 2021

Evaluation Of Two Neonatal Challenge Models For Broiler Chickens And Their Effects On Early Performance Parameters, Callie Selby

Graduate Theses and Dissertations

Formaldehyde fumigation in poultry hatch cabinets has been utilized for sanitation of hatching eggs for over a century. Formaldehyde is utilized to minimize pathogenic microbes on the surface of the egg as well as the microbial bloom during the hatching process. While formaldehyde is effective, its use is regulated in the United States and Europe due to its carcinogenic nature. Formaldehyde has been shown to damage the cuticle of the egg, cause embryonic death, and damage the epithelial lining of the respiratory tract of freshly hatched chicks, predisposing them for respiratory infection. Alternatives for formaldehyde fumigation must be identified and …


Development Of Aptamer Rolling Circle Amplification Platform As A Vaccine Adjuvant To Control Salmonella In Broiler Chickens, Abigeal Iyabode Omolewu Dec 2021

Development Of Aptamer Rolling Circle Amplification Platform As A Vaccine Adjuvant To Control Salmonella In Broiler Chickens, Abigeal Iyabode Omolewu

Graduate Theses and Dissertations

Salmonella has been a major source of concern in public health and food industry. It is the cause of gastrointestinal illness and fever called salmonellosis. Severe cases of salmonellosis have resulted in hospitalization and even death around the world. Salmonella can be found in the intestinal tract of animals including chickens and can be transmitted to human through contaminated food. Hence, it is highly important to find ways of reducing the transmission of Salmonella from chickens to humans. This work is focused on the control of Salmonella in broiler chicken through the development of novel vaccine adjuvant. Two different aptamer …


Investigation Of Histomoniasis Prevention In Poultry, Lesleigh Beer Dec 2021

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 …


Directed Genome Evolution To Identify Genes For Macrophage Survival By Staphylococcus Agnetis, Sonali Lakshika Anne Lenaduwe Lokuge Jul 2021

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 …


Survey Of Ticks And Tick-Borne Pathogens Associated With Feral Swine (Sus Scrofa) In Arkansas, Haylee Campbell May 2021

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 …


Determination Of Ownership Practices And Cytauxzoon Felis Prevalence In Domestic Felines Of Northwest Arkansas, Daniella M. Duran May 2021

Determination Of Ownership Practices And Cytauxzoon Felis Prevalence In Domestic Felines Of Northwest Arkansas, Daniella M. Duran

Animal Science Undergraduate Honors Theses

Cytauxzoon felis is a protozoan pathogen that causes the infectious disease, cytauxzoonosis in wild and domestic felines. The natural host of this pathogen is the bobcat (Lynx rufus), which is why this disease is also commonly referred to as “bobcat fever”. The C. felis pathogen infects wild and domestic cats upon transmission by infected ticks. Amblyomma americanum, also known as the Lone Star tick, the primary transmission vector for C. felis. This tick species is largely populated throughout the state of Arkansas, making C. felis a large threat to wild and domestic felines in these areas. Cytauxzoonosis is commonly thought …


Examining Pathogenesis And Preventatives In Spontaneous And Staphylococcus-Induced Bacterial Chondronecrosis With Osteomyelitis In Broilers, Nnamdi Simon Ekesi Dec 2020

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 …


Biogeography Of The Bovine Respiratory Microbiome And Its Relationship With Bovine Respiratory Disease, Jianmin Chai Dec 2020

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 …


Fate And Dissemination Of Salmonella Reading In Market-Age Turkeys At Processing Using Oral Gavage Challenge Model, Aaron Ashcraft Dec 2020

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 …


The Efficacy Of Extended-Release Eprinomectin For The Reduction Of Horn Flies, Face Flies, And Fecal Egg Counts Of Parasitic Nematodes In Replacement Beef Heifers, Sophia F. Landers May 2020

The Efficacy Of Extended-Release Eprinomectin For The Reduction Of Horn Flies, Face Flies, And Fecal Egg Counts Of Parasitic Nematodes In Replacement Beef Heifers, Sophia F. Landers

Animal Science Undergraduate Honors Theses

The purpose of this study was to evaluate the efficacy of extended-release eprinomectin against horn flies, face flies, and fecal egg counts of parasitic nematodes in crossbreed replacement beef heifers. Fifty-four heifers were randomly placed into three treatment groups (N=18 heifers/treatment). Group 1 was administered the labeled dosage of extended-release eprinomectin on day 0. Group 2 acted as the negative control. Group 3 received the anthelmintic injection once a quarter of the heifers in the group reached the threshold treatment level for horn flies (N=200 flies/animal; day 41). Nematode infections were measured via fecal egg counts while horn and face …


Evaluation Of Anthelmintic Therapies In A Fall Calving Beef Cowherd, Laine Zammit May 2020

Evaluation Of Anthelmintic Therapies In A Fall Calving Beef Cowherd, Laine Zammit

Graduate Theses and Dissertations

Internal parasitism inevitability prompts economic loss in beef cattle production by decreasing growth performance and reproductive traits. Today, the most widely used class of anthelmintic used to treat parasitism, is the macrocyclic lactone. Many studies have conflicting results on the efficacy of macrocyclic lactones (ML) efficacy against internal parasitism. The objective of this study was to evaluate the effectiveness of moxidectin and eprinomectin, two of the MLs, on cow performance. Multiparous fall calving, crossbred beef cows (n = 106) were allocated randomly to 1 of 3 anthelmintic treatments: 1) Negative control (CON), in which cows did not receive an anthelmintic, …


Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford Dec 2019

Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford

Graduate Theses and Dissertations

The economic impact of infectious bovine keratoconjunctivitis (IBK) has been documented in many parts of the world. Many researchers have observed that prevention of this disease is very difficult given current methodologies. This is primarily due to the multifactorial nature of this disease. The objective of this dissertation was to determine the impact of IBK on calf performance and estimate genetic parameters, heritability and estimated breeding values for IBK susceptibility. Data were analyzed using PROC GLIMMIX of SAS; while genetic parameters were estimated using a linear animal model for both single- and two-traits through MTDFREML. Additional evaluations calculated heritability using …


Methods To Evaluate Ruminant Animal Production Responses, Jose Manuel Diaz Gomez Dec 2019

Methods To Evaluate Ruminant Animal Production Responses, Jose Manuel Diaz Gomez

Graduate Theses and Dissertations

In experiment 1, 80 steers (197.0 kg initial body weight; BW for fall, 116.9 kg for spring), were stocked at 2.45 and 4.1 calves/ha in fall and spring, respectively in 16 tall fescue pastures [fall ergovaline (EV) = 1,475 ppb and spring EV = 1,173 ppb] under 2 treatments, mineral (MIN) (n = 8) and cumulative management (CM) (n = 8). Forage allowance did not differ (P = 0.76) between CM and MIN during fall but differed during spring (P ≤ 0.05, 2.55 vs. 3.22 kg DM/kg BW, for MIN and CM, respectively). For fall, average daily gain (ADG) resulted …