Theses and Dissertations at Montana State University (MSU)
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Item Clodronate use in yearling, exercising horses on endocrine regulation of bone growth and development(Montana State University - Bozeman, College of Agriculture, 2023) Conrad, Matthew Benjamin; Chairperson, Graduate Committee: Amanda N. BradberyExtra-label bisphosphonate use in juvenile horses is widespread despite limited scientific understanding of biological and welfare impacts on skeletally immature, exercising horses. The objective of this study was to determine the effects of clodronate on endocrine regulation of bone growth, hypothesizing there would be no effect. To test this, 32 Quarter Horses were stratified by age (500 + or - 13 d of age), BW (336 + or - 26 kg), sex (n = 16 males, n = 16 females), and initial bone optical density by aluminum equivalence into four treatment groups for a 168-d trial. The experimental period was divided into two phases mimicking sales preparation (Phase I: d 0-83) and early performance training (Phase II: d 84-168). Investigators were blinded, and all horses received iso-volumetric intramuscular injections of either 1.8 mg/kg BW clodronate disodium (OSPHOS®) or saline (placebo) on d 0, 42, 84, and 126. Treatments consisted of control (CON; n = 8), single-dose (1X; n = 8; d 84), two-dose (2X; n = 8; d 0, 84), and four-dose groups (4X; n = 8; d 0, 42, 84, 126). Physical measurements including BW, wither height (WH), hip height (HH), body length (BL), and heart girth (HG) circumference were recorded every 42 d from d 0. Serum samples were collected every 42 d prior to treatment administration to quantify growth hormone (GH), calcitonin (CT), parathyroid hormone (PTH), and ionized calcium. Data were analyzed using PROC MIXED of SAS. All physical growth parameters increased (P < or = 0.01) and growth hormone tended to decrease over time (P = 0.09) following normal growth patterns. A treatment time interaction was observed for PTH (P = 0.05) where concentrations increased on d 84 in 4X and on d 126 in 2x following the second administration of clodronate while 1X and CON remained unchanged. Ionized Ca decreased over time (P < 0.01) with no effect on CT concentrations (P > 0.33). These results suggest that while administration of bisphosphonate has no effect on growth morphometrics, its repetitive use alters PTH concentrations after two doses.Item The horses with no names: lessons from the U.S. Civil War(Montana State University - Bozeman, College of Letters & Science, 2021) Boynton, Frank Robert; Chairperson, Graduate Committee: Brett WalkerHistorians have paid insufficient attention to horses in the study of military history. The US Civil War is no exception. Horses were central to the conduct and outcome of the Civil War. They provided the essential motive power for both armies. Without them, no military strategy was feasible. They carried the charging cavalrymen. They pulled the artillery through fields and mired roads with mud so deep the horses risked drowning in it. They supported command and control as they carried leaders and their staffs. They pulled the ambulances that carried stricken men from the battlefield to hospitals. They pulled the supply wagons that supplied the armies. The horse required a universe of support to sustain it. The frequent inability of armies to provide simple hay and grain caused thousands to starve to death. The time and distance imperatives of war often strained horses beyond their capacity -- thousands died from simple exhaustion Much like the soldiers who died in the thousands from diseases, horses died by the tens of thousands from diseases for which they had no defense and for which the men charged with their care had no ability to treat. Lastly, much like the human soldiers they shared the risk of the battlefield with horses were ripped by shot and shell. This is a highly interdisciplinary study and therefore I use material from beyond history. Papers in veterinary medicine provide information on equine disease and the 1860's understanding of it. Studies into equine nutrition and about the recovery of horses from prolonged malnutrition or starvation, on the effects of sleep deprivation and others inform understanding of the horse at war. The 1860 Census and US Department of Agriculture crop reports provide insights into the ability of the Pennsylvania/Maryland/Virginia area to support large numbers of horses. This material is integrated into a framework which I use to assess the probable condition of both Union and Confederate horses. I use that assessment as a means take a fresh look at specific Civil War events and other military episodes through the lens of the condition of the horses supporting the armies.Item Investigation of adult education related to equine science in the state of Montana(Montana State University - Bozeman, 1977) Whitaker, David Dean; Chairperson, Graduate Committee: Burl WinchesterItem The effects of increased shoe weight and decreased pastern angle on gain characteristics of the trot in one equine(Montana State University - Bozeman, College of Education, Health & Human Development, 1988) Kingsbury, Nancy EnglandItem Chromium-mordanted oats and 4N-HCL insoluble ash as indicators of fecal output, dry matter digestibility and dry matter intake of horses(Montana State University - Bozeman, College of Agriculture, 1993) Barbisan, David JohnItem Prevalence of equine gastrointestinal parasites in Montana, correlation of Parascaris equorum egg per gram counts and worm burdens, and comparison of two parasite egg counting techniques for equine feces(Montana State University - Bozeman, College of Agriculture, 1976) McQueary, Carl AlbertItem Effects of psyllium supplementation on serum protein, triglycerides, electrolytes and packed cell volume in horses grazing rapidly growing cool season grasses(Montana State University - Bozeman, College of Agriculture, 2013) Helmecke, Paula; Chairperson, Graduate Committee: Shannon MoreauxThe effect of psyllium supplementation on absorption of nutrients other than glucose and water in the intestine of horses is not known. Eleven 10- to 18-yr-old light breed stock horses were used in a completely randomized design to determine the effects of psyllium supplementation on serum protein, serum triglyceride and serum electrolyte concentrations as well as PCV, water intake and feed intake. Horses were grazed individually separated with electric tape for 8 h every day. At night they were kept in individual dry lots where they received a mixed grain and a psyllium supplement. Psyllium treatment level was 1) 180 g/d psyllium or 2) an isocaloric control and 0g/d psyllium. Blood samples were collected on day 8, 15, 22, and 29 of the study and used to determine protein and triglyceride concentrations. Concentrations of serum electrolytes and packed cell volumes (PCV) were measured using blood collected on day 0, 8, 15, 22, and 29. Horses that received psyllium showed reduced concentrations of triglycerides (P < 0.001) and protein (P = 0.019) compared to those receiving an isocaloric control. No differences (P > 0.065) in the lysine and arginine concentrations were found between treatments. There were no differences (P > 0.085) in chloride and sodium concentrations, PCVs, and water and feed intake between treatments. There was a treatment by day interaction (P = 0.032) for concentrations of potassium; furthermore, the treatment effect on potassium concentrations existed only on study days 8, and 22, while no difference was found on collection days 0, 15, and 29. Supplementing horses with 180 g/d psyllium appears to have a lowering effect on serum protein and triglyceride concentrations in the intestine of horses.Item Metabolic and morphometric effects of psyllium supplementation in horses grazing rapidly growing cool season grasses(Montana State University - Bozeman, College of Agriculture, 2013) Rohrs, Jaclyn Lenae; Chairperson, Graduate Committee: Shannon MoreauxDigestion of non-structural carbohydrates (NSC) from cool season pasture grasses can result in increased adiposity, insulin resistance, and laminitis in horses. Lowering blood glucose levels and increasing insulin sensitivity can reduce disease risk. Supplementing horses with psyllium reduces blood glucose and insulin concentrations in meal fed horses. The objective of this study was to evaluate the effects of psyllium supplementation in horses grazing rapidly growing cool season grass. Eleven lightbreed stock horses (7 mares, 4 geldings, Age 13.5 + or - 2.5; mean + or - SD) were individually confined in dry lots overnight and strip grazed for 8 hours daily for 30 days. Psyllium-supplemented horses (n = 6) received 180 g of psyllium daily. All horses received an isocaloric protein supplement. Forage intake was calculated using a previously published equation based on bodyweight. Forage was analyzed for nutrient content every other week. Changes in metabolic characteristics were assessed by assay of glucose, insulin, leptin and adiponectin concentrations in blood samples collected on days 0, 8, 15, 22, and 29 at 0700, 0800, 0900, 1100, 1300, and 1500 hours. Changes in morphometric characteristics were assessed using bodyweight, body condition score, mean neck circumference, and tailhead fat mass on days 0 and 29. Significance accepted at P < 0.05. Psyllium supplementation lowered mean glucose, glucose AUC and increased time to peak glucose. There was a treatment by gender interaction for mean insulin, peak insulin, and insulin AUC. These variables were lowered to a greater extent in geldings than in mares. Higher NSC intake resulted in higher peak insulin in all horses. Older horses had higher peak insulin and decreased time to peak glucose and insulin. All characteristics of glucose and insulin decreased over the 30 day interval spent grazing pasture. Mares had higher leptin concentrations. Adiponectin concentrations increased with NSC intake. No significant differences occurred for morphometric characteristics. These results indicate that supplementing psyllium in horses grazing cool season grasses lowered systemic glucose and insulin concentrations and these effects may reduce the risk of metabolic diseases, such as laminitis. However, systemic glucose and insulin concentrations were affected to a greater extent in males than females.Item Psyllium lowers blood glucose and insulin concentrations in horses(Montana State University - Bozeman, College of Agriculture, 2010) Peterson, Jyme Lynn; Chairperson, Graduate Committee: Shannon Moreaux.The metabolic effect of feeding psyllium daily to horses is unknown. Eight 11- to 16-yr-old (Trial 1) and sixteen 7- to 16-yr-old (Trial 2; Trial 3) light breed stock horses were used in a completely randomized design to determine the effects of psyllium supplementation on BW, BCS, neck circumference, tailhead fat, plasma glucose, insulin, leptin, ghrelin, and adiponectin concentrations. An intravenous glucose challenge was also performed and the same variables were measured (Trial 3). Horses were stratified by sex and BW and put on trial for 42 d (Trial 1) and 60 d (Trial 2). Horses were individually fed a grain ration at 0.5% BW (Trial 1) and 0.25% BW (Trial 2), hay at 1.5% BW (Trial 1;Trial 2), and a psyllium treatment. Psyllium treatment levels for Trial 1 were: 1) 90 g/d psyllium or 2) an isocaloric control and 0 g/d psyllium. In Trial 2 levels of 180 and 270 g/d psyllium were added. Trial 3 took place the day after Trial 2 ended; horses were administered an intravenous dextrose solution at 0.5% BW after a 12 h fasting period. In Trial 1, horses fed psyllium had a greater (P = 0.01) increase in neck circumference than those not fed psyllium. Trial 2 revealed treatment by time interactions for glucose (P < 0.001) and insulin (P = 0.03). Glucose was lower 90 min (P = 0.05) and 120 min (P < 0.001) after a meal in horses fed psyllium compared to those not fed psyllium. Insulin concentrations were lower 90 min (P = 0.002) and 300 min (P < 0.001) in horses fed psyllium compared to those that were not. There was no difference in glucose (P = 0.48) or insulin (P = 0.15) concentrations between horses on 90, 180, or 270 g psyllium treatments. In Trial 3, horses fed psyllium had lower glucose (P = 0.03) and adiponectin (P = 0.02) concentrations than horses not fed psyllium. Supplementing horses with any level of psyllium appears to lower concentrations of plasma glucose and serum insulin after a meal.Item The economics of artificial insemination regulations in the equine breeding industry : monopoly versus transaction costs explanations(Montana State University - Bozeman, College of Agriculture, 1996) Thresher, Valerie Anne; Chairperson, Graduate Committee: Randal R. Rucker.Artificial insemination is a technological development that lowers the cost of producing livestock while providing a means for accelerating the development of genetic characteristics. The adoption of artificial insemination by the equine industry has been inconsistent across breed registries and varied over time. The question arises as to why any registry would resist the introduction of a technology that lowers the cost of production. Identification of the characteristics that influence the decision by a breed registry to place restrictions on the use of artificial insemination will provide economic reasons to explain why the restrictions exist. Various explanations are hypothesized to provide a basis for empirical models. Regression analysis is run to test for the significance of the following factors; opportunistic behavior, monopoly power, and the importance of relative versus absolute performance. It is established that all three factors contribute to a registry's decision whether or not to impose restrictions on the use of artificial insemination. There are two separate conclusions drawn from the results. Where opportunistic behavior (i.e. cheating) generates rewards not otherwise attainable, artificial insemination will be restricted. Where relative performance matters and a breed is able to exert monopoly power, artificial insemination will be restricted.