This study was undertaken to compare the absorption and retention of copper and zinc when supplemented to exercising horses in the form of sulfate or organic-chelate mineral supplements. Nine mature horses were used in a modified-switchback designed experiment consisting of seven 28-d periods. Horses were fed a diet consisting of 50% coastal Bermudagrass and 50% concentrate. All diets were balanced to meet the energy, protein, calcium and phosphorus requirements for horses performing moderate to intense exercise. Copper and zinc supplementation varied by period. During mineral depletion and repletion periods, horses respectively consumed diets with no supplemental mineral or Cu and Zn supplemented in the sulfate form to provide 100% of NRC (1989) values. In periods 4 and 7, horses were fed diets designed to provide 90% of NRC (1989) values for Cu and Zn supplied in the sulfate or organic-chelate forms. Horses were subjected to a standard exercise test on d 23 of periods 4 and 7 followed by a 4-d total fecal and urine collection. Blood samples were drawn every 28-d for determination of plasma Cu, Zn and ceruloplasmin concentration, and white blood cell counts and Cu,Zn-superoxide dismutase activity were evaluated in periods 4 and 7. Copper and zinc balance was determined from feed, fecal, urine and water samples obtained during the total collections in periods 4 and 7. Copper and Zn intake and fecal excretion were greater (P<0.05) for horses consuming the organic-chelate supplemented diet. Apparent Cu absorption as a percent of intake and retention as a percent of intake were also greater for this group. Plasma Cu, Zn and ceruloplasmin concentration was not different for horses consuming the two mineral supplement forms. White blood cell counts and superoxide dismutase activity were not affected by diet treatment. Formulation error and suspected sample contamination made it difficult to compare absorption and retention of Cu and Zn, but the use of a controlled repletion-depletion diet sequence appeared to be an effective experimental design component.

This study was undertaken to compare the absorption and retention of copper and zinc when supplemented to exercising horses in the form of sulfate or organic-chelate mineral supplements. Nine mature horses were used in a modified-switchback designed experiment consisting of seven 28-d periods. Horses were fed a diet consisting of 50% coastal Bermudagrass and 50% concentrate. All diets were balanced to meet the energy, protein, calcium and phosphorus requirements for horses performing moderate to intense exercise. Copper and zinc supplementation varied by period. During mineral depletion and repletion periods, horses respectively consumed diets with no supplemental mineral or Cu and Zn supplemented in the sulfate form to provide 100% of NRC (1989) values. In periods 4 and 7, horses were fed diets designed to provide 90% of NRC (1989) values for Cu and Zn supplied in the sulfate or organic-chelate forms. Horses were subjected to a standard exercise test on d 23 of periods 4 and 7 followed by a 4-d total fecal and urine collection. Blood samples were drawn every 28-d for determination of plasma Cu, Zn and ceruloplasmin concentration, and white blood cell counts and Cu,Zn-superoxide dismutase activity were evaluated in periods 4 and 7. Copper and zinc balance was determined from feed, fecal, urine and water samples obtained during the total collections in periods 4 and 7. Copper and Zn intake and fecal excretion were greater (P<0.05) for horses consuming the organic-chelate supplemented diet. Apparent Cu absorption as a percent of intake and retention as a percent of intake were also greater for this group. Plasma Cu, Zn and ceruloplasmin concentration was not different for horses consuming the two mineral supplement forms. White blood cell counts and superoxide dismutase activity were not affected by diet treatment. Formulation error and suspected sample contamination made it difficult to compare absorption and retention of Cu and Zn, but the use of a controlled repletion-depletion diet sequence appeared to be an effective experimental design component.

Thesis (M.S.)--California Polytechnic State University, 2010. / Title from PDF title page; viewed on March 18, 2010. Major professor: Hazelwood, Scott, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Biomedical Engineering." "February 2010." Includes bibliographical references (p. 87-89).

Inflammatory Airway Disease has been reported in young racehorses worldwide. The aim of this study was to determine the prevalence of airway inflammation in an actively racing population of horses and to describe and quantify the degree of lung lesions in this population of horses. The Ontario Death Registry program provided a unique opportunity to evaluate the lungs of actively racing horses that died or were euthanized due to catastrophic injuries while racing or training. Lung sections of 95 horses were included in the study and evaluated using a previously validated histological airway scoring system. Additionally, staining with Toluidine blue and immunohistochemical labeling was performed on a subset of horses to further characterize the inflammation. Inflammatory cell infiltration, smooth muscle hyperplasia and hemosiderin were commonly found. The airway lesion scores were significantly higher in the caudal and dorsal sections of the lungs than in other areas. There was no correlation between the individual scores and either breed, sex, age, cause of death or performance index. The inflammatory and smooth muscle scores were normally distributed and the hemosiderin score was not. The inflammatory cell infiltration was composed of mononuclear cells, with increased number of mast cells and eosinophils in 3/20 and 12/95 horses respectively. Immunohistochemical labeling showed the inflammation around the airway to be composed of 41.0% CD3-positive T cells and 5.8% CD79a-positive B cells. In addition to the airway findings, inflammatory cell aggregates were observed around the pulmonary blood vessels and in the alveolar septa in 67/95 and 71/95 horses respectively. In conclusion, this study provides a histologic evaluation of a population of actively racing horses in which airway inflammation is a common finding.

Artifacts caused by regional anesthesia can influence image interpretation of ultrasound and nuclear scintigraphy. Perineural and intrasynovial anesthesia is commonly performed prior to magnetic resonance imaging (MRI); and the effects on MR images, if any, is unknown. The objectives of this prospective, randomized, blinded experiment were to determine if perineural and intrasynovial anesthesia of structures in the equine foot cause iatrogenic changes detectable with MRI. A baseline MRI of both front feet was performed on 15 horses 2 to 6 days prior to mepivacaine injection adjacent to the lateral and medial palmar digital nerves (PDN), and into the podotrochlear bursa (PB), digital flexor tendon sheath (DFTS), and distal interphalangeal joint (DIPJ) of one randomly assigned forelimb. MRI was repeated at 24 and 72 hours post-injection; then qualitative and quantitative assessments of MRI findings were performed. The results of this study showed MRI findings associated with the PDN, PB and DIPJ at 24 and 72 hours after mepivacaine injection did not alter significantly from those at baseline. Compared to baseline, a significant increase in synovial fluid volume of the DFTS was detected with MRI at 24 and 72 hours post-injection. Therefore, perineural anesthesia of the PDN and intrasynovial anesthesia of the PB or DIPJ did not interfere with the interpretation of MRI examinations performed at 24 or 72 hours after injection. However, intrasynovial anesthesia of the DFTS caused an iatrogenic increase in synovial fluid, which was detectable on MRI for at least 72 hours. Although a definite time frame for resolution of DFTS distension was not determined, we recommend waiting greater than 3 days between intrasynovial anesthesia of the DFTS and evaluation with MRI. / Equine Guelph

Eight cecally cannulated Quarter Horse geldings were utilized in a crossover design with two 28 d periods with a 21 d washout period between. Horses were adapted to dietary treatments from d 1 to 19, dry matter intake was determined from d 20 to 24, and cecal fluid was collected on d 28. Horses were paired by age and body weight (BW) and randomly assigned to treatment. Treatments consisted of housing horses individually in stalls or group housed in a dry lot pen. Regardless of treatment, all horses were individually fed a pelleted concentrate at 1% BW (as fed) offered twice daily 12 h apart. All horses had ad libitum access to coastal bermudagrass hay. Hay was offered to stalled horses initially at 2% BW (as fed) then adjusted based on 120% of a previous 3 d average of voluntary intake. A dual marker system was utilized for estimation of voluntary intake in all horses using titanium dioxide (TiO2) as the external marker and acid detergent insoluble ash (ADIA) as the internal marker. Cecal samples were collected 4-h after the morning meal and immediately analyzed for pH. Samples were transported to the USDA/ARS laboratory to enumerate total anaerobic bacteria and lactic acid bacteria, and to determine methane and ammonia activity. Cecal pH was influenced by housing (P = 0.02) with group housed horses having lower cecal pH values when compared to stalled horses (6.52 +/- 0.04 and 6.69 +/- 0.04, respectively). The cecal pH values of this study are similar to other reported values when feeding similar diets (5). Populations of cecal total anaerobic bacteria and lactobacillus were not influenced by housing (P >= 0.21). Treatments did not affect the production of acetate, propionate, or butyrate (P &gt;= 0.15). Additionally, methane and ammonia production were not affected by treatments (P &gt;= 0.17). Forage intake was greater for group housed horses (P = 0.04) than stalled (8.47 +/- 0.89 kg DM/d and 5.17 +/- 0.89 kg DM/d, respectively). In conclusion, confinement housing did not greatly influence the cecal environment of a horse when similar diets were offered.

Microhistological analysis is a highly effective microscopic technique of determining botanical composition of animal diets by visual recognition of fecal plant fragments, and has been widely used in range studies. The objective of this study was to use microhistological techniques to predict the botanical composition of domesticated horse diets when grazing mixed cool-season pasture. Samples of tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire], Kentucky bluegrass (Poa pratensis L.) and orchardgrass (Dactylis glomerata L.) were evaluated for microscopically unique characteristics. Cool season pasture grazing studies were conducted in October 2006 and May 2007 in Lexington, KY. Eight thoroughbred mares were placed in individual paddocks of varying botanical compositions to graze for six days. For each percent increase of tall fescue or orchardgrass in the paddock, there was a corresponding increase of 0.44% and 0.42%, respectively, in the diet. In conclusion, microhistological analysis is a useful tool for determining botanical composition of horse diets when grazing cool season grass pastures.

No description available.

Thesis (M.Sc.(Microbiology)--University of Pretoria, 2006. / Summary in English. Includes bibliographical references.

Thesis (Ed. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 198-210). Also available via the Internet.