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Characterization Of A Dexamethasone-Immunosuppressed C57bl/6n Mouse Model For Chronic Cryptosporidiosis, Edward G. Martin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cryptosporidium parvum is a coccidian protozoan that colonizes epithelial cells lining respiratory and digestive tracts of animals and humans. Cryptosporidiosis is a well-recognized zoonotic disease infecting primarily neonates and immunocompromised hosts, including human immunodeficiency virus-infected patients. Clinical disease is manifested as a chronic diarrheal illness that is self-limiting in immunocompetent hosts and prolonged and often life-threatening in hosts with compromised immune systems. The lack of a suitable small animal model for screening anti-cryptosporidial drugs and for examining the pathogenicity and immunobiology of chronic cryptosporidosis was the impetus for this research effort.

The objectives of the present study were three-fold: to …

Effects Of Rumen-Protected Amino Acids On Production In Holstein Cows, David Paul Dawson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Six nonlactating Holstein cows fitted with rumen and duodenal cannula were used to determine the efficacy of pH sensitive fatty acid polymer encapsulation as a means protecting amino acids from rumen fermentation and as a post-ruminal amino acid delivery system. The cows were arranged in a 2 X 2 factorial in a Latin Square design. Treatments were 1) the basal ration, and 2) basal ration plus rumen-protected lysine, methionine, and threonine at 10 g each per day.

Rumen parameters measured were pH, ammonia, volatile fatty acids, protozoa, liquid, and dry matter rate of passage, total viable bacteria, and viable cellulolytic …

Treatment Of Low Quality Forages By Hydrogen Peroxide And(Or) Anhydrous Ammonia And Their Utilization In Ruminant Nutrition, Mohammed Diouri

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three experiments were conducted to evaluate low quality forages treatment by anhydrous ammonia (NH₃) and(or) hydrogen peroxide (H₂O₂).

In experiment I, a control and three treatments of barley straw were compared: NH₃, NH₃ after rehydration of the straw with water (NH₃+H₂O), and NH₃ after rehydration with a H₂O₂ solution (NH₃+H₂O₂). Forages were fed, with a supplement, at two levels of intake (ad libitum and 75% of ad lib.). Treatments were administered in a split-plot in a Latin …

Resource Partitioning Among Brown Bears At Brooks River In Katmai National Park And Preserve, Alaska, Tamara L. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A quantitative study of the behavior of brown bears (Ursus arctos) was undertaken in areas of different human activity at Brooks River in Katmai National Park and Preserve, 1988-1990. The research was conducted to determine whether the activity of any particular classes of bears using the river were differentially affected by human activity, activity of conspecifics, or availability of salmon. Approximately 1643 hours of systematic observation were recorded, 781 between June 26 and July 29 and 862 hours between August 26 and October 12 of all three years. Comparisons of fish capture rates by bears and distributions of …

Fat Content Of American Kestrels (Falco Sparverius) And Sharp-Shinned Hawks (Accipiter Striatus) Estimated By Total Body Electrical Conductivity, Shari M. Harden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Total body electrical conductivity (TOBEC) is a noninvasive method for the estimation of lean mass in live subjects. Lipid content can be calculated from the body mass measured and the lean mass estimated from TOBEC. I used live American Kestrels (Falco sparverius) to study the accuracy of this method. TOBEC measurements were compared to actual body content determined by Soxhlet fat extraction using petroleum ether as the solvent. TOBEC estimated 73.7% of the variation in lean mass in a sample of 21 kestrels. The use of restraining devices (Vetrap and cardboard cylinders) altered the TOBEC measurement but only …

Gregarious Behavior In Large Mammals: Modeling, Methodology, And Application, Thomas L. Morton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gregarious behavior of ungulates was considered in four ways. The first concern was W. D. Hamilton's hypothesis that a simple movement rule could reduce predation risk and encourage grouping behavior. Simulations showed little effect of this nearest-neighbor rule on predation risk. Similar, more complicated rules reduced predation risk by up to two thirds.

The second focus was on the accuracy of ground observers in diagramming individual animal locations in small herds of elk. A remotely controlled airplane was used to photograph the herds from above. A substantial distance discrepancy was found between "true" and "observed" animal locations. This discrepancy increased …