Veterinary Microbiology and Immunobiology Commons^™

Type X Strains Of Toxoplasma Gondii Are Virulent For Southern Sea Otters (Enhydra Lutris Nereis) And Present In Felids From Nearby Watersheds, Karen Shapiro, Elizabeth Vanwormer, Andrea Packham, Erin Dodd, Patricia A. Conrad, Melissa Miller

School of Veterinary and Biomedical Sciences: Faculty Publications

Why some Toxoplasma gondii-infected southern sea otters (Enhydra lutris nereis) develop fatal toxoplasmosis while others have incidental or mild chronic infections has long puzzled the scientific community. We assessed robust datasets on T. gondii molecular characterization in relation to detailed necropsy and histopathology results to evaluate whether parasite genotype influences pathological outcomes in sea otters that stranded along the central California coast. Genotypes isolated from sea otters were also compared with T. gondii strains circulating in felids from nearby coastal regions to assess land-to-sea parasite transmission. The predominant T. gondii genotypes isolated from 135 necropsied sea otters were atypical Type …

Contact Rates With Nesting Birds Before And After Invasive Snake Removal: Estimating The Effects Of Trap-Based Control, Amy A. Yackel Adams, Melia G. Nafus, Page E. Klug, Björn Lardner, M.J. Mazurek, Julie A. Savidge, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive predators are responsible for almost 60% of all vertebrate extinctions worldwide with the most vulnerable faunas occurring on islands. The brown treesnake (Boiga irregularis) is a notorious invasive predator that caused the extirpation or extinction of most native forest birds on Guam. The success of avian reintroduction efforts on Guam will depend on whether snake-control techniques sufficiently reduce contact rates between brown treesnakes and reintroduced birds. Mouse-lure traps can successfully reduce brown treesnake populations at local scales. Over a 22-week period both with and without active snake removal, we evaluated snake-trap contact rates for mouse- and bird-lure traps. Bird-lure …

An Evaluation Of The Registration And Use Prospects For Four Candidate Toxicants For Controlling Invasive Mongooses (Herpestes Javanicus Auropunctatus), Emily W. Ruell, Chris N. Niebuhr, Robert T. Sugihara, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The eradication or control of invasive small Indian mongooses from islands likely requires toxic baiting when removal by trapping proves insufficient. The one toxic bait currently registered for mongooses in the United States has relatively low palatability and efficacy for mongooses. Developing and registering a new pesticide can be very expensive, while funding for developing toxicants for mongooses is limited. Once registered, use of a toxic bait may be hindered by other factors, such as public opposition to an inhumane toxicant, poorer efficacy than expected, or if the toxic bait is difficult for applicators to apply or store. Therefore, we …

Transmission Dynamics Of Toxoplasma Gondii In Arctic Foxes (Vulpes Lagopus): A Long-Term Mark-Recapture Serologic Study At Karrak Lake, Nunavut, Canada, Emilie Bouchard, Stacey A. Elmore, Ray T. Alisauskas, Gustaf Samelius, Alvin A. Gajadhar, Keaton Schmidt, Sasha Ross, Emily J. Jenkins

United States Department of Agriculture Wildlife Services: Staff Publications

Transmission dynamics of Toxoplasma gondii, a parasite of importance for wildlife and human health, are enigmatic in the Arctic tundra, where free-ranging wild and domestic felid definitive hosts are absent and rarely observed, respectively. Through a multiyear mark-recapture study (2011– 17), serosurveillance was conducted to investigate transmission of T. gondii in Arctic foxes (Vulpes lagopus) in the Karrak Lake region, Nunavut, Canada. Sera from adult foxes and fox pups were tested for antibodies to T. gondii by using serologic methods, including the indirect fluorescent antibody test, direct agglutination test, and modified agglutination test. The overall seroprevalence was 39% in adults …

Not All Surveillance Data Are Created Equal—A Multi‐Method Dynamic Occupancy Approach To Determine Rabies Elimination From Wildlife, Amy J. Davis, Jordona D. Kirby, Richard B. Chipman, Kathleen M. Nelson, Tatiana Xifara, Colleen T. Webb, Ryan Wallace, Amy T. Gilbert, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. A necessary component of elimination programmes for wildlife disease is effective surveillance. The ability to distinguish between disease freedom and non‐detection can mean the difference between a successful elimination campaign and new epizootics. Understanding the contribution of different surveillance methods helps to optimize and better allocate effort and develop more effective surveillance programmes.

2. We evaluated the probability of rabies virus elimination (disease freedom) in an enzootic area with active management using dynamic occupancy modelling of 10 years of raccoon rabies virus (RABV) surveillance data (2006–2015) collected from three states in the eastern United States. We estimated detection probability …

Impact Of Beta-Adrenergic Agonist Supplementation And Heat Stress On The Microbiome And Gastrointestinal Transcriptome Of Sheep, Erin Margaret Duffy

Department of Animal Science: Dissertations, Theses, and Student Research

Improving animal growth and efficiency are critical points of research as the world’s population and demand for agriculture products increase. Therefore, adaptions or changes in the gut are of interest to maximize growth efficiency and wellbeing of livestock. The gastrointestinal tract of the rumen plays many critical roles with the assistance of the associated microbial community. One way to improve animal performance is supplementation of β-adrenergic agonists (β-AA) which are commonly fed to cattle during the last 20-40 days of the finishing period, improving muscle growth by decreasing adipose deposition and increasing muscle accretion. Two β-AA, Ractopamine HCl (β1-AA) and …

Survival, Fidelity, And Dispersal Of Double-Crested Cormorants On Two Lake Michigan Islands, Christopher R. Ayers, Katie C. Hanson-Dorr, Ken Stromborg, Todd W. Arnold, Jacob S. Ivan, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Colony fidelity and dispersal can have important consequences on the population dynamics of colonial-nesting birds. We studied survival and inter-colony movements of Double-crested Cormorants (Phalacrocorax auritus; cormorants) nesting at Spider and Pilot islands, located 9 km apart in western Lake Michigan, during 2008–2014. We used live resighting and dead recovery data from both colonies, plus dead recoveries from throughout North America, in a multistate live and dead encounter model to estimate annual survival, inter-colony movements, plus temporary and permanent emigration to unmonitored sites. Annual survival averaged 0.37 (annual process variation, ˆ = 0.07) for hatch-year, 0.78 (ˆ= 0.08) for secondyear, …

Use Of Unmanned Aircraft Systems (Uas) And Multispectral Imagery For Quantifying Agricultural Areas Damaged By Wild Pigs, Justin W. Fischer, Kelsey Greiner, Mark W. Lutman, Bryson L. Webber, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) cause extensive damage to agricultural crops, resulting in lost production and income. A major challenge associated with assessing damage to crops is locating and quantifying damaged areas within agricultural fields. We evaluated a novel method using multispectral high-resolution aerial imagery, collected from sensors mounted on unmanned aircraft systems (UAS), and feature extraction techniques to detect and map areas of corn fields damaged by wild pigs in southern Missouri, USA. Damaged areas were extracted from orthomosaics using visible and near-infrared band combinations, an object-based classification approach, and hierarchical learning cycles. To validate estimates we also collected ground …

Confronting Models With Data: The Challenges Of Estimating Disease Spillover, Paul C. Cross, Diann J. Prosser, Andrew M. Ramey, Ephraim M. Hanks, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

For pathogens known to transmit across host species, strategic investment in disease control requires knowledge about where and when spillover transmission is likely. One approach to estimating spillover is to directly correlate observed spillover events with covariates. An alternative is to mechanistically combine information on host density, distribution and pathogen prevalence to predict where and when spillover events are expected to occur. We use several case studies at the wildlife–livestock disease interface to highlight the challenges, and potential solutions, to estimating spatiotemporal variation in spillover risk. Datasets on multiple host species often do not align in space, time or resolution, …

Typha (Cattail) Invasion In North American Wetlands: Biology, Regional Problems, Impacts, Ecosystem Services, And Management, Sheel Bansal, Shane C. Lishawa, Sue Newman, Brian A. Tangen, Douglas Wilcox, Dennis Albert, Michael J. Anteau, Michael J. Chimney, Ryann L. Cressey, Edward Dekeyser, Kenneth J. Elgersma, Sarah A. Finkelstein, Joanna Freeland, Richard Grosshans, Page E. Klug, Daniel J. Larkin, Beth A. Lawrence, George Linz, Joy Marburger, Gregory Noe, Clint Otto, Nicholas Reo, Jennifer Richards, Curtis Richardson, Leroy Rodgers, Amy J. Schrank, Dan Svedarsky, Steven Travis, Nancy Tuchman, Lisamarie Windham-Myers

United States Department of Agriculture Wildlife Services: Staff Publications

Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural …

Failure Of Oxysterols Such As Lanosterol To Restore Lens Clarity From Cataracts, Damian M. Daszynski, Puttur Santhoshkumar, Ashutosh S. Phadte, K. Krishna Sharma, Haizhen A. Zhong, Marjorie F. Lou, Peter F. Kador

School of Veterinary and Biomedical Sciences: Faculty Publications

The paradigm that cataracts are irreversible and that vision from cataracts can only be restored through surgery has recently been challenged by reports that oxysterols such as lanosterol and 25-hydroxycholesterol can restore vision by binding to αB-crystallin chaperone protein to dissolve or disaggregate lenticular opacities. To confirm this premise, in vitro rat lens studies along with human lens protein solubilization studies were conducted. Cataracts were induced in viable rat lenses cultured for 48 hours in TC-199 bicarbonate media through physical trauma, 10 mM ouabain as Na+/K+ ATPase ion transport inhibitor, or 1 mM of an experimental compound that induces water …

Extreme Site Fidelity As An Optimal Strategy In An Unpredictable And Homogeneous Environment, Brian D. Gerber, Mevin B. Hooten, Christopher P. Peck, Mindy B. Rice, James H. Gammonley, Anthony D. Apa, Amy J. Davis

United States Department of Agriculture Wildlife Services: Staff Publications

1. Animal site fidelity structures space use, population demography and ultimately gene flow. Understanding the adaptive selection for site fidelity patterns provides a mechanistic understanding to both spatial and population processes. This can be achieved by linking space use with environmental variability (spatial and temporal) and demographic parameters. However, rarely is the environmental context that drives the selection for site fidelity behaviour fully considered.

2. We use ecological theory to understand whether the spatial and temporal variability in breeding site quality can explain the site fidelity behaviour and demographic patterns of Gunnison sage‐grouse (Centrocercus minimus). We examined female site fidelity …

Ecological Interventions To Prevent And Manage Zoonotic Pathogen Spillover, Susanne H. Sokolow, Nicole Nova, Kim M. Pepin, Alison J. Peel, Juliet R.C. Pulliam, Kezia Manlove, Paul C. Cross, Daniel J. Becker, Raina K. Plowright, Hamish Mccallum, Giulio A. De Leo

United States Department of Agriculture Wildlife Services: Staff Publications

Spillover of a pathogen from awildlife reservoir into a human or livestock host requires the pathogen to overcome a hierarchical series of barriers. Interventions aimed at one or more of these barriers may be able to prevent the occurrence of spillover. Here, we demonstrate how interventions that target the ecological context in which spillover occurs (i.e. ecological interventions) can complement conventional approaches like vaccination, treatment, disinfection and chemical control. Accelerating spillover owing to environmental change requires effective, affordable, durable and scalable solutions that fully harness the complex processes involved in cross-species pathogen spillover.

This article is part of the theme …

Scavenging In The Anthropocene: Human Impact Drives Vertebrate Scavenger Species Richness At A Global Scale, Esther Sebastián‐González, Jomar Magalhães Barbosa, Juan M. Pérez‐García, Zebensui Morales‐Reyes, Francisco Botella, Pedro P. Olea, Patricia Mateo‐Tomás, Marcos Moleón, Fernando Hiraldo, Eneko Arrondo, José A. Donázar, Ainara Cortés‐Avizanda, Nuria Selva, Sergio A. Lambertucci, Aishwarya Bhattacharjee, Alexis Brewer, Erin Abernethy, Olin E. Rhodes Jr., Kelsey Turner, James C. Beasley, Travis L. Devault, Andrés Ordiz, Camilla Wikenros, Barbara Zimmermann, Petter Wabakken, Christopher C. Wilmers, Justine A. Smith, Corinne J. Kendall, Darcy Ogada, Evan R. Buechley, Ethan Frehner, Maximilian L. Allen, Heiko U. Wittmer, James R.A. Butler, Johan T. Du Toit, John Read, David Wilson, Klemen Jerina, Miha Krofel, Rich Kostecke, Richard Inger, Arockianathan Samson, Lara Naves‐Alegre, José A. Sánchez‐Zapata

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large‐scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion‐consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using …

The Economic Impacts Of Blackbird (Icteridae) Damage To Sunflower In The Usa, Karina Ernst, Julie Elser, George Linz, Hans Kandel, Jason Holderieath, Samantha Degroot, Steven Shwiff, Stephanie Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Blackbird (Icteridae) damage to ripening sunflower (Helianthus annuus L.) has been a persistent economic issue in the USA for the last five decades. To quantify losses, we surveyed blackbird damage from 2001 to 2013 (excluding 2004) to physiologically mature sunflower in eight states: North Dakota, South Dakota, Texas, Nebraska, Minnesota, Colorado, Kansas, and Vermont.

RESULTS:We pooled data gathered during the most recent 5 years (2009 to 2013) of the survey and found losses averaged $US2.5 million and $US11.3 million for confectionery and oilseed hybrids, respectively. Three states, North Dakota, South Dakota, and Nebraska, had sufficient acreage and bird damage …

Habitat Selection By American Beaverat Multiple Spatial Scales, Guiming Wang, Lance F. Mcclintic, Jimmy D. Taylor

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Semiaquatic mammals require both aquatic and terrestrial habitats, particularly interfaces between the two habitats. As ecosystem engineers, American beaver (Castor canadensis) consume and fell a great amount of deciduous trees. We tested the prediction that open water and amounts of food resources, including hardwood forests (i.e., deciduous trees as the dominant form of vegetation), herbaceous and woody wetlands, and shrubs, would influence the second-order habitat selection (i.e., placing home ranges on the landscape) by American beaver, whereas the third-order habitat selection of American beaver would be associated with woody wetland and shrub edges. We investigated hierarchical habitat selection by …

Epidemic Growth Rates And Host Movement Patterns Shape Management Performance For Pathogen Spillover At The Wildlife–Livestock Interface, Kezia R. Manlove, Laura M. Sampson, Benny Borremans, E. Frances Cassirer, Ryan S. Miller, Kim M. Pepin, Thomas E. Besser, Paul C. Cross

United States Department of Agriculture Wildlife Services: Staff Publications

Managing pathogen spillover at the wildlife–livestock interface is a key step towards improving global animal health, food security and wildlife conservation. However, predicting the effectiveness of management actions across host–pathogen systems with different life histories is an on-going challenge since data on intervention effectiveness are expensive to collect and results are system-specific.We developed a simulation model to explore how the efficacies of different management strategies vary according to host movement patterns and epidemic growth rates. The model suggested that fast-growing, fast-moving epidemics like avian influenza were best-managed with actions like biosecurity or containment, which limited and localized overall spillover risk. …

Young Germ Cell Depleted Ovaries In Post-Reproductive Mice And Its Effects On Immune Function, Mckenna Walters

Undergraduate Honors Capstone Projects

It has previously been shown that young, cycling ovarian transplantation in aged female mice increased the general health and life span in regard to their post-reproductive health. It has further been hypothesized that this enhancement of health is directly influenced by the ovarian somatic cells. To address this hypothesis, transplants of young germ cell depleted and germ cell containing ovaries were performed on female mice. The purpose of this study is to continue to discern the reproductive influence on aging health, specifically in the area of immunological well-being. Control group mice were separated by age and treatment mice were subsequently …

Preparation And Evaluation Of Single-Stranded Dna Aptamer-Based Immunological Adjuvant In Broiler Chickens, Adil Sabr Al-Ogaili

Graduate Theses and Dissertations

Mineral oils and metal salts are commonly used as adjuvants to enhance acquired immunity. Recently, monoclonal antibodies (MAbs) and recombinant peptides agonist CD40 receptor have shown remarkable promise for induction of rapid and robust immune responses. Limitations of this approach MAb production costs and multiple administrations due to anti-MAb immune responses. Here we demonstrate the development of a unique and sophisticated DNA aptamer-based alternative for CD40-directed delivery of universal antigens as an alternative in chickens, and potentially other vertebrate species. This receptor, expressed by antigen-presenting cells, acts as a costimulatory molecule for activated T helper lymphocytes. After initially selecting for …

Board Invited Review: Prospects For Improving Management Of Animal Disease Introductions Using Disease-Dynamic Models, Ryan S. Miller, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Management and policy decisions are continually made to mitigate disease introductions in animal populations despite often limited surveillance data or knowledge of disease transmission processes. Science-based management is broadly recognized as leading to more effective decisions yet application of models to actively guide disease surveillance and mitigate risks remains limited. Disease-dynamic models are an efficient method of providing information for management decisions because of their ability to integrate and evaluate multiple, complex processes simultaneously while accounting for uncertainty common in animal diseases. Here we review disease introduction pathways and transmission processes crucial for informing disease management and models at the …

The One Health Approach To Toxoplasmosis: Epidemiology, Control, And Prevention Strategies, A. Alonso Aguirre, Travis Longcore, Michelle Barbieri, Haydee Dabritz, Dolores Hill, Patrice N. Klein, Christopher Lepczyk, Emily L. Lilly, Rima Mcleod, Judith Milcarsky, Caroline E. Murphy, Chunlei Su, Elizabeth Vanwormer, Robert Yolken, Grant C. Sizemore

School of Veterinary and Biomedical Sciences: Faculty Publications

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, …

Transposon Mutagenesis In Mycobacterium Avium Subspecies Paratuberculosis, John P. Bannantine, Denise K. Zinniel, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

While transposon mutagenesis has been developed for Mycobacterium avium subspecies paratuberculosis (Map), relatively few laboratories have adopted this important genetic tool to examine gene function and essentiality. Here we describe the construction of a Map transposon library using the Himar1 mariner transposon, but concepts can also be applied to the Tn5367 transposon, which has also been used by our group. Delivery of the transposon is by a temperature-sensitive phagemid, ϕMycoMarT7, and plating transductants requires patience and specialized media due to length of incubation required to observe colonies. Several transposon mutants obtained from these libraries have been tested in vaccine and …

Environmental Transmission Of Toxoplasma Gondii: Oocysts In Water, Soil And Food, Karen Shapiro, Lillian Bahia-Oliveira, Brent Dixon, Aurélien Dumètre, Luz A. De Wit, Elizabeth Vanwormer, Isabelle Villena

School of Veterinary and Biomedical Sciences: Faculty Publications

Toxoplasma gondii is a zoonotic protozoan parasite that can cause morbidity and mortality in humans, domestic animals, and terrestrial and aquatic wildlife. The environmentally robust oocyst stage of T. gondii is fundamentally critical to the parasite's success, both in terms of its worldwide distribution as well as the extensive range of infected intermediate hosts. Despite the limited definitive host species (domestic and wild felids), infections have been reported on every continent, and in terrestrial as well as aquatic environments. The remarkable resistance of the oocyst wall enables dissemination of T. gondii through watersheds and ecosystems, and long-term persistence in diverse …

Improving Risk Assessment Of The Emergence Of Novel Influenza A Viruses By Incorporating Environmental Surveillance, Kim M. Pepin, Matthew W. Hopken, Susan A. Shriner, Erica Spackman, Zaid Abdo, Colin Parrish, Steven Steven, James O. Lloyd-Smith, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Reassortment is an evolutionary mechanism by which influenza A viruses (IAV) generate genetic novelty. Reassortment is an important driver of host jumps and is widespread according to retrospective surveillance studies.However, predicting the epidemiological risk of reassortant emergence in novel hosts from surveillance data remains challenging. IAV strains persist and cooccur in the environment, promoting co-infection during environmental transmission. These conditions offer opportunity to understand reassortant emergence in reservoir and spillover hosts. Specifically, environmental RNA could provide rich information for understanding the evolutionary ecology of segmented viruses, and transform our ability to quantify epidemiological risk to spillover hosts. However, significant challenges …

Individual-Level Antibody Dynamics Reveal Potential Drivers Of Influenza A Seasonality In Wild Pig Populations, Kim M. Pepin, Kerri Pedersen, Xiu-Feng Wan, Fred L. Cunningham, Colleen T. Webb, Mark Q. Wilber

United States Department of Agriculture Wildlife Services: Staff Publications

Swine are important in the ecology of influenza A virus (IAV) globally. Understanding the ecological role of wild pigs in IAV ecology has been limited because surveillance in wild pigs is often for antibodies (serosurveillance) rather than IAVs, as in humans and domestic swine. As IAV antibodies can persist long after an infection, serosurveillance data are not necessarily indicative of current infection risk. However, antibody responses to IAV infections cause a predictable antibody response, thus time of infection can be inferred from antibody levels in serological samples, enabling identification of risk factors of infection at estimated times of infection. Recent …

Using Dna To Identify The Source Of Invasive Mongooses, Herpestes Auropunctatus (Carnivora: Herpestidae) Captured On Kaua‘I, Hawaiian Islands, Darren J. Wostenberg, Matthew W. Hopken, Aaron B. Shiels, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Two small Indian mongooses (Herpestes auropunctatus) were live-captured in 2012 at separate locations on the Hawaiian Island of Kaua'i, which was previously considered to be free of this invasive species. Genotypes from these two individuals were compared to genotypes of H. auropunctatus from the islands of Hawai'i (n =39), O'ahu (n =91), Maui (n = 39), and Moloka'i (n = 19) to determine the island of origin of the Kaua'i individuals. Genotypes were generated from each individual using five microsatellite loci. Genetic clustering was estimated by Bayesian inference of spatial clustering of individuals and …

Reducing Prairie Dog Populations And Damage By Castration Of Dominant Males, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Black-tailed prairie dogs (Cynomys ludovicianus) occur widely across the prairie states of North America. They compete with livestock for forage, transmit plague, and damage lawns, landscaping, and property. Interest in non-lethal methods, such as immunocontraception, is growing; however, reductions in the population due to contraception may be offset by increases in survival because adults and yearlings are not subject to the energetic demands of reproduction, and lower densities may increase the amount of resources available to growing offspring. Surgical sterilization provides a means for modeling these effects. Thus, we castrated males prior to the 1998 breeding season to simulate the …

Rumen Microbial Culture Library And In Vitro Analysis Of Selected Bacterial Species On Colonization Resistance Against Bovine Enteric Pathogens, Maria Antony

Electronic Theses and Dissertations

The anaerobic habitat of the four chambers in ruminant’s foregut plays a vital role in the fermentation of the food by the active involvement of the residing microbial community. The cultivability and the potential role of rumen bacteria in the field of livestock production, host health and immunity are important to study. The developed anaerobic culturing techniques enable us to culture and screen different rumen bacteria to study the anti-pathogenic effects. Whole genome sequencing and analysis help us to understand the genome level characteristics of the rumen bacterial species individually. Since the majority of the rumen biosphere is still not …

Novel Amphiphilic Cyclobutene And Cyclobutane Cis-C18 Fatty Acid Derivatives Inhibit Mycobacterium Avium Subsp. Paratuberculosis Growth, Denise K. Zinniel, Wantanee Sittiwong, Darrell D. Marshall, Govardhan Rathnaiah, Isin T. Sakallioglu, Robert Powers, Patrick H. Dussault, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

Mycobacterium avium subspecies paratuberculosis (Map) is the etiologic agent of Johne’s disease in ruminants and has been associated with Crohn’s disease in humans. An effective control of Map by either vaccines or chemoprophylaxis is a paramount need for veterinary and possibly human medicine. Given the importance of fatty acids in the biosynthesis of mycolic acids and the mycobacterial cell wall, we tested novel amphiphilic C₁₀ and C₁₈ cyclobutene and cyclobutane fatty acid derivatives for Map inhibition. Microdilution minimal inhibitory concentrations (MIC) with 5 or 7 week endpoints were measured in Middlebrook 7H9 base broth media. We compared the …

Investigation Of Congestive Heart Failure In Beef Cattle In A Feedyard At A Moderate Altitude In Western Nebraska, Rodney A. Moxley, David R. Smith, Dale M. Grotelueschen, Tom Edwards, David Steffen

School of Veterinary and Biomedical Sciences: Faculty Publications

Right-sided congestive heart failure (brisket disease) commonly occurs in cattle raised at elevations >2,500– 3,500 m. We investigated clinical cases resembling brisket disease at a western Nebraska feedyard at a moderate altitude (1,369 m). Over a 15-mo period (2009–2010), we examined 17 cases (16 steers and 1 heifer), all purebred Angus. All animals had clinical right-sided heart failure: brisket and ventral abdominal edema, and severe chronic passive congestion of the liver. Gross examination confirmed right ventricular hypertrophy (left ventricle plus septum: right ventricle weight ratio mean: 1.33 vs. 2.8–4.0 reference interval). Microscopically, all 17 cases had interstitial fibrosis (mean score: …