Life Sciences Commons^™

Physiological Changes Associated With Pregnant Or Nonpregnant Mares Grazing Pastures Of Orchardgrass-Bluegrass, Kentucky 31 Tall Fescue Infected With Epichloë Coenophiala, Or Kyfa9821 Tall Fescue Infected With The Novel Endophyte Ar584, Victoria A. Taylor

Theses and Dissertations--Veterinary Science

Kentucky 31 tall fescue (KY31) infected with the common toxic endophyte strains of Epichloё coenophiala produces toxic alkaloids that improve plant vigor, but cause numerous adverse effects in grazing animals. Researchers developed a variety of KY31 containing an alternative strain of E. coenophiala, termed novel endophyte (NE). Adverse health effects in mares have not been evaluated.

Experiments in this thesis tested the hypothesis that the NE pasture does not cause adverse effects typically associated with KY31. Specific aims were to: 1) compare forage ergovaline concentrations between KY31 vs NE pastures; 2) evaluate palmar artery diameters in mares grazing KY31, …

Biology And Detection Of Pregnanes During Late Gestation In The Mare, Michelle Arelia Ann Wynn

Theses and Dissertations--Veterinary Science

Progesterone in the mare declines to almost undetectable concentrations in late gestation. It’s metabolized into several pregnanes, some circulating at very high concentrations. Although the function of many pregnanes remains unclear, 5α-dihydroprogesterone and allopregnanolone are bioactive. Measurements of pregnanes in late gestation are typically by immunoassay, although results are confounded by cross-reactivity with related pregnanes. Conversely, liquid chromatography tandem mass spectrometry (LC-MS/MS) allows differentiation of individual pregnanes. The purposes of these studies were: 1) to evaluate the ability of a 5α-reductase inhibitor, dutasteride, to alter pregnane metabolism and pregnancy outcome, 2) to evaluate changes in target pregnanes in late gestation …

Lymphocyte-Mediated Inflamm-Aging In The Horse, Melissa Hope Siard

Theses and Dissertations--Veterinary Science

Senior horses (≥20 years) exhibit inflamm-aging, or chronic, low-grade inflammation that occurs systemically with aging, similarly to humans. Inflamm-aging has previously been characterized in the horse in circulation as well as specifically being mediated by lymphocytes and monocytes. In humans, inflamm-aging has been associated with increased morbidity and mortality. However, in the horse, relatively little about inflamm-aging is known regarding clinical effects or factors influencing severity. The contribution of lymphocytes to inflamm-aging of senior horses was examined, specifically through determining the relationships of inflamm-aging with various other health parameters, effects of seasonality, and the extent to which inflamm-aging can be …

Differences In Behavioral And Physiological Variables Measured With Precision Dairy Monitoring Technologies Associated With Postpartum Diseases, I Ching Tsai

Theses and Dissertations--Animal and Food Sciences

The transition period is defined as the three weeks before and three weeks after the cow calves. Transition cow diseases are considered production diseases. Precision dairy monitoring (PDM) technologies measure physiological, behavioral, and production indicators on individual animals to improve management strategies and farm performance. The objective of the first study was to assess how hypocalcemia, hyperketonemia, and metritis affected variables measured by PDM technologies. The objective of the second study was to use variables from multiple commercially available PDM to examine alert performance generated from different analyses.

Precision Dairy Farming Technology Solutions For Detecting Dairy Cow Disease To Improve Dairy Cow Well-Being, Amanda Stone

Theses and Dissertations--Animal and Food Sciences

Dairy cow health is multifactorial and complex. High producing dairy cows have been described as metabolic athletes, but metabolic and infectious diseases around calving affect many cows. These diseases have drastic negative effects on dairy cow well-being, milk production, and dairy farm economics. Early disease detection could potentially improve disease management, treatment, and future prevention techniques. The first objective of this research was to evaluate the use of activity, lying behavior, reticulorumen temperature, and rumination time determined by precision dairy farming technologies to detect transition cow diseases including hypocalcemia, ketosis, and metritis. The second objective was to evaluate the ability …

An Examination Of Milk Quality Effects On Milk Yield And Dairy Production Economics In The Southeastern United States, Derek T. Nolan

Theses and Dissertations--Animal and Food Sciences

Mastitis is one of the most costly diseases to dairy producers around the world with milk yield loss being the biggest contributor to economic losses. The objective of first study of this thesis was to determine the impacts of high somatic cell counts on milk yield loss. To accomplish this, over one million cow data records were collected from Southeastern US dairy herds. The objective of the second study was to determine optimum treatment cost of clinical mastitis by combining two economic modeling approaches used in animal health economics. The last objective of this thesis was to determine how much …

Proteome Basis Of Muscle‐Specific Beef Color Stability, Mahesh Narayanan Nair

Theses and Dissertations--Animal and Food Sciences

Fresh beef color is critical to consumers’ purchase decisions, and beef color stability is muscle-specific. Sarcoplasmic proteome plays a critical role in beef color stability. This dissertation focuses on the proteome basis of inter- and intra-muscular variations in beef color.

The first experiment examined the sarcoplasmic proteome of three beef muscles with differential color stability, i.e., longissimus lumborum (LL), psoas major (PM), and semitendinosus (ST), during wet-aging. LL, PM, and ST (n = 8) were subjected to wet-aging for 0, 7, 14, and 21 days. On each aging day, steaks were fabricated, and color and other biochemical attributes were evaluated …

Influence Of Ergot Alkaloids On Rumen Motility: Time And Concentration Of Ergovaline + Ergovalinine Required To Impact Reticulorumen Motility, Kara Riccioni

Theses and Dissertations--Animal and Food Sciences

Fescue toxicosis is problematic for ruminant livestock, causing weight loss and low productivity when fed endophyte-infected forages. Complete underlying mechanisms of toxicosis are unknown therefore; the objective of the study was to determine if ruminally dosed ergot alkaloids impact rumen motility. Cannulated steers were pair-fed a forage diet and ruminally dosed with endophyte-free (E-) or endophyte-infected (E+) tall fescue seed. An 8-h period of rumen motility collection began 4-h after feeding by monitoring pressure change via a wireless telemetry and transducer system. In experiment 1, steers were paired by weight and assigned to E- or E+ treatment. Overall, E+ steers …

Assessment Of Bovine Vascular Serotonin Receptor Populations And Transport Of Ergot Alkaloids In The Small Intestine, Miriam A. Snider

Theses and Dissertations--Animal and Food Sciences

Prior work using a contractility bioassay determined that the serotonin (5-HT) receptor subtype 5-HT_2A is present in bovine lateral saphenous veins and plays a role in ergot alkaloid-induced vascular contraction in steers grazing endophyte-infected (Epichloë coenophiala) tall fescue (Lolium arundinaceum). A study was conducted to determine what 5-HT receptors are involved in vasoconstriction of bovine gut vasculature. The findings of this study indicate that 5-HT_2A is present and may play a role in ergot alkaloid induced vasoconstriction. A second study was conducted to determine if ergot alkaloids were transported in the small intestine. The …

Behavioral Gait Change Characterization And Detection Using Precision Dairy Monitoring Technologies, Barbara Wadsworth Jones

Theses and Dissertations--Animal and Food Sciences

Lameness is a painful disorder that decreases performance and is highly recognized as one of the most important health and welfare concerns for dairy cattle. Visual gait scoring is the most common way to detect gait change in dairy cattle. However, this is not only subjective, but is also time consuming and costly. A need to remove the subjective assessment of human observation exists. Therefore, automatic gait change detection for continuous monitoring by precision dairy monitoring technologies may be beneficial. The first objective of this research was to characterize behavior and production variables as cow gait changed to evaluate potential …

Molecularly Imprinted Polymers Synthesized As Adsorbents For Ergot Alkaloids: Characterization And In Vitro And Ex Vivo Assessment Of Effects On Ergot Alkaloid Bioavailability, Manoj B. Kudupoje

Theses and Dissertations--Animal and Food Sciences

Alkaloid toxicities negatively impact livestock health and production and are of serious economic concern to animal industries. To date, few strategies have been developed to evaluate alkaloid levels in feed or to counteract alkaloid toxicities. The present research evaluated the applicability of imprinting technology to synthesize polymers that have potential to interact with ergot alkaloids and therefore reduce their bioavailability in the GIT. The studies also evaluated applicability of synthesized polymers for use in the ruminal environment using an in vitro ruminal fermentation model, and for the ability to ameliorate vasoconstriction using ex vivo myographic evaluations.

In the first experiment, …

Genomic Perspectives On Amphibian Evolution Across Multiple Phylogenetic Scales, Paul Michael Hime

Theses and Dissertations--Biology

Genomes provide windows into the evolutionary histories of species. The recent accessibility of genome-scale data in non-model organisms and the proliferation of powerful statistical models are now providing unprecedented opportunities to uncover evolutionary relationships and to test hypotheses about the processes that generate and maintain biodiversity. This dissertation work reveals shallow-scale species boundaries and population genetic structure in two imperiled groups of salamanders and demonstrates that the number and information content of genomic regions used in species delimitation exert strong effects on the resulting inferences. Genome scans are employed to test hypotheses about the mechanisms of genetic sex determination in …