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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Nutritional Interrelationships between Iron, Copper and Manganese in Domestic Livestock

Hansen, Stephanie Laura 04 December 2008 (has links)
Oftentimes the diets of cattle and pigs contain levels of iron well beyond the nutritional requirement of the animal. This superfluous iron may come from feedstuffs naturally high in iron, or from the consumption of soil, though bioavailability of iron from soil is unknown. Additionally, excess iron in cattle diets has been shown to negatively impact the metabolism of manganese and copper, though the molecular mechanism behind this interaction is unclear. The purpose of this research was threefold: 1) to determine the effect of ensiling on bioaccessibility of iron from soil contamination of corn greenchop, 2) to identify proteins important in iron metabolism in bovine and swine, and 3) to determine if these proteins are affected by dietary iron concentration. The results reported herein suggest that bioaccessibility of iron from soil contamination is greatly increased when soil undergoes a prolonged exposure to a low pH environment, such as that found with fermenting forages. These data indicate that very little iron from soil is available to the animal if no prior exposure to an acidic environment occurs. Also, for the first time we report that several proteins known to be essential to iron metabolism in rodents are present in bovine small intestine and liver. Specifically, the iron importer divalent metal transporter 1, the iron exporter ferroportin, and the multi-copper ferroxidase hephaestin were all present in bovine duodenum. In the bovine, reduced iron status, as induced by a primary deficiency of copper, resulted in increased gene expression of divalent metal transporter 1 and ferroportin in duodenum and decreased expression of the ferroportin regulatory hormone hepcidin and divalent metal transporter 1 in liver. Protein expression of ferroportin and hephaestin were also increased in duodenum due to reduced iron status. The addition of excessive amounts of iron to the diets of young calves also appeared to regulate protein expression of transporters important in iron metabolism. Specifically, high iron tended to decreased duodenal protein levels of divalent metal transporter 1 and reduced ferroportin protein levels, though no effect on hephaestin was observed. We also examined iron metabolism in the young pig, in order to examine the effect of an iron deficient diet on expression of these proteins. We found that hephaestin protein in the duodenum was lowered by feeding a high iron diet, and levels of both ferroportin and divalent metal transporter 1 tended to be reduced by high dietary iron compared to pigs fed a low iron diet. Additionally, we found that feeding a high iron diet to pigs negatively impacted liver concentrations of manganese. And feeding a high iron diet to either pigs or calves reduced duodenal concentrations of manganese, suggesting that high dietary iron reduces manganese absorption. Because high iron diets fed to both pigs and calves tended to reduce duodenal levels of divalent metal transporter 1, a protein known in rodents to transport both iron and manganese, it appears that the observed reductions in duodenal manganese concentrations may be a result of reduced transporter availability. Collectively, our data suggest that high dietary iron may negatively affect manganese absorption, and because the iron content of livestock diets is often high, further research is warranted.
52

Whey Permeate, Delactosed Permeate, and Delactosed Whey as Ingredients to Lower Sodium Content of Cream Based Soups

Dixon, Elizabeth Marie 05 December 2008 (has links)
The use of whey permeates as salt substitutes can help to decrease sodium and chloride intake, increase potassium, calcium and magnesium intakes and decrease hypertension risk. Five different whey permeates from 5 different manufacturers were analyzed with ICP for mineral content (Na, K, Ca, Mg, Fe, Zn). Two permeates are powder and three are liquid. Lactose and protein content were also analyzed by Lactose/D-Glucose UV kit from Roche and BCA protein assay, respectively. Chloride and phosphate were measured spectrophotometrically. Basic tastes and aromas were quantified by a trained sensory panel. Based on the highest âsalty tasteâ identified by the trained sensory panel, one liquid and one solid permeate were further investigated as sodium substitutes. The sodium content of the guideline solutions for comparing salty taste of the permeates were used to calculate the equivalent concentrations of salt and permeate for salty taste in aqueous solution. Two soup formulations were used to test the use of permeate as a salt substitute; one retorted, canned, condensed cream soup base, and one fresh cream soup base. Each formulation of soup was tested on a separate day by 75 consumer panelists who averaged between 20 and 30 years of age. Four samples were given each day 0%, 50%, 100% of the standard salt content in condensed soup, and permeate at a content calculated to be equal in salty taste to the standard salt content. The permeate soup was ranked in salty taste slightly lower than the 50% sample for the fresh soup. In the retorted soups, the permeate was ranked slightly higher than the 50% sample. However, the fresh and retorted soup formulations made from permeate actually contained 11% and 19% sodium as compared to the 100% salt recipe, respectively. The permeate soup was described as higher in salty taste than expected based on actual sodium content, but not as high as predicted from the salty taste of the permeate in aqueous solution. Potassium and magnesium levels were increased in the formulations with permeate. This research gives an optimistic view on the possibility of whey permeates and their capability of replacing sodium in cream soups and other processed foods.
53

The Impact of Nutrition on the Development of Urolithiasis in Captive Giraffes and Meat Goats.

Sullivan, Kathleen Elizabeth 27 April 2007 (has links)
Obstructive urolithiasis is a documented problem in domestic ruminants, such as the meat goat, and also in captive giraffe. A survey of the health history, feeding practices, and dietary contents in captive giraffes in North America was conducted to examine the possible connection between diet and the development of urolithiasis. Samples of urine, serum and feed were collected and analyzed for basic panels and mineral content. There appeared to be a positive correlation between diet and physiologic phosphorus levels in giraffe. This may not have been related to the ingredients of the diet but rather to the ratio of concentrate to hay eaten and the nutrient composition of the concentrate. We hypothesized that high phosphorus content in the diet and a high level of concentrate feeding would increase indicators of urolith formations including crystal formation and high urine mineral content. We followed up with a metabolic trial in meat goats, testing 2 different complete pelleted feeds and 2 complete pelleted feed to hay ratios in a 2 by 2 factorial randomized complete block design. The intent of this study was to look at the impact of type of diet (ADF-16 or Wild Herbivore complete pelleted feed) and complete pelleted feed to hay ratios (20 or 80 % hay) on the development of urolithiasis in meat goats, in the context of captive giraffe feeding practices. The four treatments had a range of fiber content and differed in mineral content, particularly Ca to P ratio and levels of P. We also measured the number of crystals in the fresh urine, as these may be considered precursors to urolith formation. The ADF-16 diet where hay was 20% of the diet had the lowest levels of fiber, lowest Ca to P ratio, and highest level of phosphorus compared to the other 3 diet treatments. From our results, it can be concluded that feeding the ADF-16 diet where hay is 20% of the diet, produced a trend of high urinary P, high serum P and a tendency for a high crystal count in the urine over the four week experimental period. These can be considered strong risk factors for the development of phosphatic uroliths. As one third of the zoos which responded to the survey fed a majority of their diets as ADF-16, this conclusion warrants further investigation.
54

Nutritional Influences on the Ultra-structural Development of the Small Intestinal Epithelium of the Perinatal Turkey Embryo and Poult

Bohórquez, Diego V 11 January 2010 (has links)
The transition from a lipid-rich in-ovo environment to a carbohydrate- and protein-rich diet is perhaps the biggest challenge that hatchlings must overcome during early life. Amniotic fluid supplementation of the late-term avian embryo (i.e. in-ovo feeding â IOF) stimulates enteric maturation of poultry and alleviates the stress of hatching. Because rapidly dividing cells (e.g. intestinal epithelial cells) require an exogenous supply of nucleotides, dietary nucleotide supplementation can improve the enteric maturation post-hatch. Our working hypothesis was that nutritional strategies influencing in-ovo nutrition and post-hatch dietary feed intake enhance the enteric development in perinatal turkey embryos and poults. Our study was among the first to characterize the ultra-structural changes in the small intestinal mucosa of the perinatal turkey embryo and poult (Chapter II). Moreover, electron microscopy revealed that microbial colonization in the avian digestive tract begins prior to hatch as early as 17E. Molecular profiling of these bacteria confirmed that some the species include Bacillus, Lactobacilli, Pseudomonas and several uncultured bacteria (Chapter III). We showed that IOF accelerates the ultra-structural maturation of the jejunum mucosa of turkey embryos and poults around the time of hatch, and these effects are associated with elevated plasma triiodothyronine (T3) levels, a potent stimulator of morphological development of the mucosa (Chapter IV). Finally, we showed that dietary nucleotide supplementation to IOF turkey poults enhances the enteric maturation after hatch and the positive effects of nucleotide supplementation appear to be associated with stimulation of feed intake post-hatch. Therefore, we concluded that: (1) profound ultra-structural adaptations of the intestinal mucosa coincide with the imbibition of the amniotic fluid by the embryo; (2) microflora colonization of the avian gut begins well before hatch, (3) IOF stimulates ultra-structural maturation of the small intestine at hatch and these effects involve up-regulation of genes mediating epithelial cell proliferation as well as higher T3 levels. (4) Dietary nucleotide supplementation of IOF turkey poults enhances enteric maturation post-hatch, which coincide with a consistent stimulation of poults appetite by dietary nucleotide supplementation.
55

BIOAVAILABILITY OF OIL-BASED AND&szlig-LACTOGLOBULIN COMPLEXED VITAMIN AIN A RAT MODEL

SHAW, JU-JEAN 16 October 2000 (has links)
<p>SHAW, JU-JEAN. Bioavailability of Oil-Based and &szlig-Lactoglobulin Complexed Vitamin A in a Rat Model. (Chair: Jonathan C. Allen and Co-chair: Harold E. Swaisgood)The goal of this research was to determine the bioavailability of a retinyl palmitate-&szlig-lactoglobulin complex in fortified skim milk and non-milk liquids using a rat model. Vitamin A plays a crucial role in many biological functions such as vision, cell differentiation, gene expression, central nervous system development, bone development and immune system function. Fluid milk products have been fortified with vitamin A (along with Vitamin D) since the 1930s to reduce the incidence of disorders caused by fat-soluble vitamin deficiency in the USA. Low-fat and non-fat fluid milk products are fortified with vitamin A and other nutrients to restore that which is removed with the lipid phase. Vitamin A preparations for milk fortification have either oil-based carriers or water-based carriers. Although it was suggested that the oil-in-water emulsions are preferred rather than oil-based preparation, vitamin A- fortified milk is often unable to comply with nutrition labeling requirements. Because retinyl palmitate, a vitamin A form most used in food products, can bind with &szlig-lactoglobulin, a major component of bovine whey, in a molar ratio of 2:1, we propose &szlig-lactoglobulin could be a carrier to fortify skim milk with retinyl palmitate. The bioavailability of this vitamin A-&szlig-lactoglobulin complex has not been tested yet so we designed and conducted experiments to test the bioavailability of this complex in the skim milk and water-based liquids.<P>
56

Role Of Membrane Lipids in Developing Insulin resistant Diabetes Mellitus Type II in Caucasians and African Americans.

Allen, Hengameh G. 01 December 2000 (has links)
<p>Insulin resistance in diabetes (DMII) can result from membrane lipid (PM) changes. Membrane lipids play a major role in hormonal signal transduction and in appropriate amounts of such molecules may lead to either decreased, or increased membrane fluidity. Therefore, in this study we determined whether PM differences exist between African Americans (BL) and Caucasians (W) and if differences contribute to impaired insulin binding (IB) in DMII. Methodology: Subjects were recruited from Caucasian Control (CC) (n=10), African American Control (AC) (n=10), Caucasian Diabetics (CD) (n=5), African American Diabetics (AD) (n=10) groups. The diabetics were type II diabetics on daily insulin injections (age and sex-matched in both racial groups). The evaluations consisted of: three day dietary record, serum total cholesterol (TC), triglyceride (TRG), very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL), glucose (Glu), hemoglobin A1C (A1C), insulin (Ins) levels and RBC membrane lipid composition including, fatty acids, phospholipids (PL), cholesterol (CH) and RBC insulin binding (IB), RESULTS: Cholesterol intake did not show any correlations with any blood constituents, membrane lipids or membrane properties. The macronutrient intake did not show a significant correlation with blood lipid levels, membrane properties and the anthropometric measurements as expected. The triglyceride levels were higher in diabetics (P <0.01). The lipoprotein evaluation indicated significant differences in VLDL (P <0.01), LDL (P <0.05) and HDL (P <0.0001) levels between control and diabetic subjects. There were no racial differences seen among the four groups. Diabetics had higher CH and it correlated with Glu (r= 0.65, P<0.05) and IB (r= -0.61, P <0.05). The CH/PL revealed strong correlation between LDL (r=0.42, P <0.01) and HDL (r= -0.56, P <0.05). The PM trans fatty acid levels (TFA) were highest in AD (P <0.01), but no correlations with IB & Glu. The PM saturated/polyunsaturated ratio (S/P) was higher in diabetics (P <0.05) correlating with insulin level (r= 0.42, P <0.01) & IB (r= -0.45, P <0.05), but no correlations with serum lipids occurred. The PL analysis showed no significant group differences for phosphatidyl inositol (PI) levels; however, significant racial differences were observed in phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC). The W showed higher PE levels than BL and lower PC. The RBC rheological (PE/PS) properties (deformability) was lower in diabetics and AC than CC. The saturated nature of RBC [(SPH+PC)/(PE+PS)] was the lowest in CC (P< 0.056). The combination of increased S/P, and increased saturated nature, decreased PE/PS, increased CH/PL indicate decreased membrane fluidity and decreased RBC deformability, which might contribute to decreased IB in DMII. Differences in PE and PC levels between BL and W possibly indicate a racial difference in cause of insulin resistance. The racial differences in developing DMII need to be recognized so the therapeutic agents can target the exact problem in the metabolic pathway to correct the insulin resistance.<P>
57

Role of Dietary Calcium and Dairy in Modulating Oxidative Stress, Inflammatory Stress and Lifespan

Bruckbauer, Antje Eerenstein 01 August 2009 (has links)
Oxidative stress and inflammatory stress have been implicated as a cause of tissue damage in multiple organ systems, leading to the development of chronic diseases such as obesity, diabetes, hypertony and atherosclerosis. They are also recognized as major factors contributing to the physiological process of aging. Previous studies have demonstrated that dietary calcium regulates reactive oxygen species production (ROS) production in adipocytes in vitro and in vivo, and inhibits adipocyte-derived inflammatory cytokine expression by suppression of calcitriol. In addition, high calcium diets modulate energy metabolism and partitioning between adipose tissue and muscle resulting in a decrease in fat storage and an increase in fat oxidation in muscle. Providing calcium in form of dairy appears to cause greater effects than supplemental calcium in both mice and humans, most likely mediated by additional components in dairy products such as branched-chain amino acids (BCAA) and angiotensin converting enzyme inhibitor (ACEi) peptides. In consideration of the multiple effects of dietary calcium and other components of dairy on adipocyte and muscle metabolism, a high density oligonucleotide microarray approach was used to identify common and differential pathways related to energy metabolism, inflammation and oxidative stress in adipose and muscle tissue in response to milk and milk components. In addition, considering the protective role of dietary calcium against oxidative and inflammatory stress, which otherwise accelerate the process of aging, a lifespan study in a mouse model of diet- induced obesity was conducted to evaluate the effects of dietary calcium from both non-dairy and dairy sources on mouse lifespan and on lifespan-related biomarkers. The results of this research confirm that calcium and BCAA contribute to the alteration of energy partitioning between adipose tissue and muscle and provide new evidence for calcium independent effects of BCAA and ACEi in energy metabolism and inflammation. Further, present data demonstrate that milk diet attenuates adiposity, protects against muscle loss and reduces oxidative and inflammatory stress. Although these did not alter maximum lifespan, they significantly suppressed early mortality.
58

Conversations: The commitment to breastfeed among low-income women in East Tennessee

Joyce, Stephanie Marie 01 August 2009 (has links)
The purpose of this qualitative study was to explore the experiences of low-income breastfeeding women in East Tennessee. Participants were recruited from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and from a birth registry housed at the university. Eligibility criteria included women who were currently breastfeeding infants less than 9 months of age and were income-eligible for WIC. Data were collected through audiorecorded in-depth telephone interviews. Eighteen interviews were conducted. Recording error led to only 16 interviews being available for analysis. However, saturation was still achieved. Transcripts were coded by a coding team, using standard coding techniques. Using grounded theory and cluster analysis, major themes emerged including aversions to formula-feeding, commitment to overcome the challenges of breastfeeding, desire for additional support, and assessing abilities through comparison with others‟ experiences. In conclusion, results of this qualitative work indicate that low-income women who choose to breastfeed recognize the differences of others‟ breastfeeding experiences and are aware of difficulties that can arise with either breastfeeding or formula-feeding.
59

Implementation of Healthier School Meals: Education and Acceptance

McGee, Nicole Lynn 01 December 2009 (has links)
Background As part of a Coordinated School Health Program project to improve the nutrition quality of school meals, a series of nutrition education and culinary training in-service workshops were conducted followed by the implementation of healthier menu options. The objectives of this study were 1) to evaluate the effect of the training on food service employees’ attitudes about nutrition, self-efficacy for preparing healthier meals, and meal preparation behavior changes and 2) to determine the plate waste percentages of school meals and school meal participation rates before and after healthier school meals were implemented. Methods The study was completed in a rural East Tennessee school district. The subjects were 12 food service employees. Three workshops, two-hours each, and one full day workshop were planned and conducted by a registered dietitian, chef, and public health nutrition graduate student for the food service employees. Pre-, post-, and follow-up questionnaires were administered to participants. Following the conclusion of the workshops, three plate waste measurements were completed in each elementary school, using a random sample of students’ trays in grades first through sixth. These measurements were completed at baseline, after the healthier menu options were implemented, and at four weeks follow-up. Results The nutrition education and culinary training in-service workshops improved the food service employees’ self-efficacy for preparing healthier school meals. The plate waste results at School 1 indicated no significant change in plate waste from baseline to after implementation of healthier school meals. No significant change in lunch, but significantly increased waste for breakfast at School 2 after implementation (P<.001) and at follow-up (P<.001). School 3 showed significantly increased waste for breakfast after implementation (P<.001) and at follow-up (P<.001) and lunch after implementation (P<.001) and at follow-up (P<.001). Conclusion Educating food service employees is an important step in implementing healthier menu items. However additional efforts may be necessary throughout the school to encourage the support of principals, parents, and teachers to help promote children’s consumption of healthier menu items.
60

An Examination of the Education, Credentials, and Functions of School Food Service Directors in Tennessee Public School Districts

Anderson, Elizabeth T 01 August 2007 (has links)
Childhood overweight and the associated health consequences have become a significant health problem in the United States and particularly in the state of Tennessee, with 14.8% of U.S. and 20.0% of Tennessee youth’s aged 10-17 currently classified as being overweight (1). Environmental factors play a significant role in the etiology of overweight, and therefore need to be considered in efforts undertaken to address this problem. Schools are one such environment where U.S. children spend a great deal of time, making the school food environment, which includes all foods available in schools (such as foods served in the school meals, a la carte foods, school stores, and school vending machines), an important contributor to the nutritional health of today’s children. The school food environment may be influenced by the education, training, and experience of the school food service director as well as the functions and availability of a Registered Dietitian in the school district. Therefore, this research study was designed to examine the education and qualifications of school food service directors in public school districts in Tennessee and to investigate the characteristics of Registered Dietitians in the structure of school nutrition programs. This research found that the requirements for the food service director position in Tennessee public school districts generally exceeds the average national position requirements and that food service directors in Tennessee have higher levels of education than their counterparts across the nation. However, certain characteristics of Tennessee school districts such as smaller size and rate of economic disability in the school district were associated with less desirable characteristics in the food service director position such as lower requirements for the position and lower education and credential levels of the individual in the food service director position. Many changes are underway in school health and child nutrition programs in Tennessee and this research provides necessary baseline information on which legislation to establish education and credentials requirements for food service directors can be pursued.

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