Master of Science / Department of Animal Sciences and Industry / Jim Nelssen / Six experiments using 3,659 nursery and finishing pigs were conducted to evaluate the effects of dietary soybean hulls and ingredient processing in corn-soybean meal or corn-soybean meal-DDGS diets on nursery and finishing performance. Experiment 1 tested increasing soybean hulls (0, 5, 10, 15, and 20%) and increasing soybean hulls decreased ADG and G:F. Experiment 2 evaluated increasing soybean hulls (0, 10, and 20%) in diets balanced or not for NE and showed reduced performance with increasing soybean hulls. Balancing for NE resulted in G:F similar to pigs fed the control. Experiments 3 and 4 evaluated increasing dietary soybean hulls in corn-soybean meal and corn-soybean meal-DDGS diets. Soybean hulls in either diet worsened G:F and improved caloric efficiency, suggesting current INRA (2004) values for soybean hulls underestimate their energy value. Experiment 5 evaluated 10 and 20% ground or unground soybean hulls in meal and pelleted diets. Caloric efficiency improved with high levels of soybean hulls. Pelleting improved ADG and eliminated negative effects on G:F with increasing soybean hulls, while grinding soybean hulls reduced performance. Experiment 6 tested increasing ground and unground soybean hulls (0, 7.5, and 15%). Increasing soybean hulls worsened G:F, carcass yield, and hot carcass weight. Grinding soybean hulls to finer particle sizes did not improve ADG and worsened G:F. Experiments 7 and 8 evaluated the replacement of corn with wheat and crystalline amino acids in nursery and finishing pig diets. Replacing 50% of corn with wheat did not affect growth performance in either nursery or finishing; however 100% replacement of corn with wheat reduced performance. In addition, feeding wheat improved carcass fat IV, while use of high levels of crystalline amino acids in wheat-based diets did not influence performance in either study. Experiment 9 evaluated the replacement of soybean meal with high-protein dried distiller’s grains with solubles and crystalline amino acids. High-protein DDGS and crystalline AA can replace 50% of the SBM in finishing diets without negatively affecting performance or carcass yield. Replacing 100% of SBM with high-protein DDGS reduced growth rate, but increasing crystalline AA levels can help mitigate negative effects on carcass yield and fat IV.

Master of Science / Department of Animal Sciences and Industry / Evan C. Titgemeyer / Seven ruminally cannulated heifers approximately 225 kg initial BW were used in a 7 × 4 Youden square design to determine the effects of different levels of limonene on ruminal Fusobacterium necrophorum populations. Treatments included: 1) control, 2) limonene at10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples were collected on d 0 (before treatment initiation), 4, 7, and 10 for measuring F. necrophorum by most probable number (MPN) method using selective culture medium. Results indicate that CRINA-L (P = 0.52) and tylosin (P = 0.19) did not affect ruminal F. necrophorum populations. Limonene linearly decreased (P = 0.03) F. necrophorum populations, and the optimal dietary concentration for limonene was 40 mg/kg DM. Limonene did not affect ruminal degradation rate of lysine, NH3 concentration, or VFA profiles in ruminal fluid. Limonene was useful for reducing ruminal concentrations of F. necrophorum. It may have potential to control liver abscesses, although further research will be needed to assess the effect of limonene under feedlot conditions.

Doctor of Philosophy / Department of Hospitality Management and Dietetics / Junehee Kwon / The purpose of this study was to assess the food choices and consumption of soldiers and their satisfaction with current and initial military training (IMT) menu standards through a survey and analysis of food selection and consumption. Participants were recruited during lunch periods before and three weeks after implementing IMT menu standards, which are healthier than current menu standards, in an Army dining facility (DFAC). Direct observations, digital photography, and plate waste methods were used to assess soldiers’ food selection and consumption. A survey was also administered to determine soldiers’ attitudes toward health, nutrition knowledge, reported food selection and consumption behaviors, and overall satisfaction with meals served under the two menu standards. Food selection and consumption were evaluated using the Army’s Go for Green Nutrition Labeling Program and the Military Dietary Reference Intakes (MDRIs). Descriptive and inferential statistics were calculated to summarize and compare data, and to identify potential associations among variables. A total of 172 and 140 soldiers participated before and after the menu change, respectively. Soldiers’ food selection patterns were similar to the proportion of green-, yellow-, and red-labeled items offered in the DFAC under both menu standards and significantly improved after the intervention (p<0.001). Soldiers consumed 886 kcal (38.6% from total fat and 11.2% from saturated fat) and 1784 mg of sodium before the menu change. Three weeks after the change, all figures improved (705 kcals, 31% of kcals from total and 9% from saturated fat, and 1339 mg of sodium) (p<0.01). Overall satisfaction and meal acceptability before and after the intervention were not different, and “food appeal” ratings actually improved. With the exception of sugar-sweetened beverage consumption, attitudes toward health were significantly associated with all reported food behaviors (p<0.01) but not with actual behaviors (p>0.05). Nutrition knowledge significantly influenced some but not all aspects related to attitudes toward health. Perceived hunger levels were positively associated with intakes of calories, protein, total fat, sodium, and cholesterol (p<0.05). Findings suggest that implementing the IMT menu standards in non-trainee Army DFACs is feasible and has the potential to improve the overall healthfulness of soldiers’ food selection and consumption.

Master of Science / Department of Human Nutrition / Tandalayo Kidd / Objective: The aims of this study were to test the effectiveness of a 15-month intervention in reducing sugar-sweetened beverage (SSB) consumption among college students and to assess fruit and vegetable intake and physical activity habits and their relationship to SSB consumption in order to improve health outcomes. Design: Randomized, controlled study. Participants: One hundred and fifty-six college students (18-24 y) from a Midwestern university, primarily female (72%), white (89%) and freshmen (51%). Intervention: Participants were randomized to control and intervention groups. Participants in the control group received no information on healthful behaviors. The intervention occurred in two stages: 1) Participants received three stage-tailored messages on healthful behaviors weekly for 10 weeks; 2) After the 3-month physical assessment, participants received 3 stage-tailored messages monthly and one email encouraging them to visit the portal page. Main Outcome Measure(s): Stages of Change for physical activity and fruit and vegetable intake; self-reported physical activity scores, self-reported fruit and vegetable intake and SSB consumption habits. Analysis: Changes in SSB consumption patterns were determined using generalized linear mixed models and linear regression models tested associations between fruit and vegetable intake, physical activity and SSB consumption. Linear mixed models were used to explore relationship between stage of change and fruit and vegetable intake and physical activity. Results: The 15-month intervention did not significantly reduce SSB consumption in the intervention group (p > 0.05). Participants recorded low fruit and vegetable intake and moderate physical activity scores. Conclusions and Implications: The high SSB consumption and low fruit and vegetable intake observed could increase students’ risk for weight gain and obesity-related conditions. Thus, college campuses can help student maintain physical activity behavior while helping them to improve their eating habits.

Doctor of Philosophy / Department of Human Nutrition / Mark D. Haub / Background: Dietary fiber has been shown to help improve several metabolic disorders including obesity and type II diabetes. However, the mechanism by which this occurs is poorly understood. Purpose: This study was designed to compare the effects of energy restriction and dietary fiber and subsequent production of short chain fatty acids on body composition, biomarkers of health, and hepatic and myocellular expression of key regulators of lipid metabolism Methods: Crossbred gilts (n=17) were randomly assigned to either a control (CON), high fiber (HF) or energy restricted (ER) diet for 42 days. Gilts on the CON and HF diets were fed ad libitum. The ER Gilts were pair fed HF gilts and matched for body weight gain. Blood samples were collected and glucose, insulin, triglycerides, non-esterified fatty acids and short chain fatty acids (SCFA) concentrations were measured. Liver and muscle tissue were biopsied and expression of peroxisome proliferator-activated receptor gama (PGC-1α) and carnitine palmitoyltransferase 1 (CPT1) were determined via RT-PCR. Results: HF gilts had significantly higher plasma TG and lower NEFA concentrations when compared to the CON and ER. The HF diet elicited a significant increase in all plasma SCFA concentrations. No differences in fold change of myocyte CPT1 and PGC-1α mRNA expression were found while they tended to be lower in hepatic samples of the HF gilts. HF gilts also had a lower (P < 0.05) back fat thickness when compared to the ER even though energy intakes were similar. Minimal changes were observed in fasting glucose and insulin as a result of diet. Conclusions: Gilts consuming a diet high in dietary fiber (DF) significantly altered their plasma lipid profiles independently to that of energy restriction and body weight and appears to be a result of plasma SCFA concentration. DF and/or SCFA appear to have minimal affects on CPT1 and PGC-1α in the liver and muscle of gilts.

Doctor of Philosophy / Department of Human Nutrition / Weiqun Wang / Anthocyanins are flavonoid pigments that account for the purple color in many plant foods. It has been investigated that anthocyanins’ predominant occurrences in human diet and their health beneficial activities such as antioxidant, anti-inflammatory, and anti-carcinogenetic effects. Based on those scientific evidences, anthocyanins are now recognized as potential therapeutic compounds. Particularly, the chemopreventive effect of anthocyanins has been widely studied by many researchers in nutrition. However, their bioactivities are diverse due to different chemical structures of anthocyanins from different sources. In this study, we discuss the chemopreventive activity of anthocyanins from purple sweet potato. Previously, we selected a purple-fleshed sweetpotato clone, P40, crossbred seeds obtained from the International Potato Center in Lima, Peru. We hypothesized that anthocyanins enriched P40 may provide health beneficial activities in cancer prevention. For the first part of this study, we analyzed nutrient compositions, dietary fiber content, anthocyanins contents, total phenolics contents and total antioxidant activity. Even thought P40 presents similar composition and amount of nutrients with the control cultivars, white-fleshed O’Henry and yellow-fleshed NC Japanese, HPLC-MS analysis confirmed that it possesses much higher anthocyanin content even up to 7.5g/kg dry matter. Also, dietary fiber, particularly soluble dietary fiber content, total phenolics content, and total antioxidant capacity of P40 were significantly higher. For the second part of the study, we tested the potential anticancer characteristic of P40 cultivar in human colonic SW480 cancer cells and in azoxymethane-induced aberrant crypt foci in mice. Treatment with 0 – 40 μM of peonidin-3-glucoside or P40 extract containing corresponding amount of anthocyanins resulted in inhibition of cell growth in a dose-dependent manner. Interestingly, even though the patterns of growth inhibition were similar in the two treatment groups, the cells treated with P40 extract tend to survive significantly less than those treated with peonidin-3-glucoside. Cell cycle analysis confirmed that the growth inhibition was not due to cytotoxicity, but cytostatic mechanism with increased number at the G1 phase of the cell cycle. The cell cycle arrest was also significantly correlated with the anthocyanin contents in P40 cultivar when compared with the white-fleshed O’Henry and yellow-fleshed NC Japanese controls. After Azoxymethane (AOM) or saline injected mice were fed basal AIN-93M diet or diets containing 10~30% of P40, 20% O’Henry or 20% NC Japanese for 6 weeks, aberrant crypt foci (ACF) multiplicity was significantly inhibited by 10~30% P40 diet. Imunohistochemistry results of colonic mucosa showed that the expression level of apoptosis marker, caspase-3, was significantly induced in the mice treated with 10~20% P40 diet. Also, PCNA expression level, which is proliferation marker, was significantly inhibited by the 30% P40 diet. These findings indicated that consuming a purple sweet potato, P40, may prevent colon cancer by modulating antioxidant status, inducing apoptosis, and reducing cell proliferation.

Doctor of Philosophy / Department of Human Nutrition / Tonatiuh Melgarejo / Obesity is a metabolic disease accompanied by a disruption in the immune system leading to systemic inflammation and susceptibility to infections. Leptin, the peptide secreted by adipocytes in proportion to fat mass, is primarily a metabolic hormone translating the body’s energy status to the brain. Leptin is also a pro-inflammatory cytokine and leptin deficiency is associated with higher infection susceptibility and a protection against autoimmune diseases. Leptin’s dual metabolic-immune function places this hormone as the link between metabolic disturbances of obesity and the immune system. In the following research projects, the contribution of leptin to both inflammation and infection susceptibility was investigated in a murine model of diet-induced obesity. Chimeric mice with leptin receptor-deficient bone marrow were resistant to HFD-induced weight and fat mass gain. These mice exhibited less inflammation in the adipose tissue demonstrated by a blunted increase in tnfa and il6 gene transcript levels, a higher prevalence of anti-inflammatory macrophages and a lower number of crown-like structures. Systemically, these mice showed a tendency towards higher insulin sensitivity. These outcomes were compared to those from mice with wild-type bone marrow. Obese and lean mice exhibited similar kinetics of bacterial clearance and systemic leptin changes following infection with Ehrlichia chaffeensis in vivo. Nevertheless, isolated “obese” peritoneal macrophages were significantly less phagocytic than macrophages from lean mice and supplementation with leptin significantly increased the obese macrophages' phagocytic activity with no effect on lean macrophages. A cell line, DB-1, derived from leptin receptor-deficient bone marrow was immortalized and characterized. This cell line has phenotypic and functional properties characteristic of macrophages, lacks the long isoform of the leptin receptor, and is unresponsive to leptin. The data from the above mentioned studies suggest that leptin contributes to the inflammation of obesity. They also suggest that leptin affects macrophage function in obesity in vitro though more studies are required to assess leptin’s contribution to infection outcomes in vivo. Finally, DB-1 cells provide a dependable tool to study further the role of leptin in obesity-associated inflammation and immune system dysregulation.

Master of Science / Department of Human Nutrition / Mark Haub / The purpose of this review is to examine the role of heart rate variability (HRV) as a predictor of athletic readiness and performance and assess whether nutrition strategies can be implemented to create favorable HRV indices with the goal of improving athletic readiness and performance. The balance between training and recovery is crucial for reaching an optimal adaptation and avoiding overtraining, allowing for improved readiness to train and compete. The measurement of HRV is non-invasive and is used primarily to quantify physical and mental stress in athletes by monitoring the effects of the autonomic nervous system on the heart. Current data suggests a relationship between resting parasympathetic tone, via time and frequency domains, and athletic performance. Parasympathetic modulated HRV indices have been associated with performance metrics such as peripheral work capacity, aerobic power, running and sprint performance, swimming performance, weight lifting performance, anaerobic capacity, strength, and enhanced mental focus/skill execution. The use of nutrition to help enhance sports performance is becoming more common. Evidence-based sports nutrition provides fuel for training/competition, assists in maximizing training adaptations, enhances recovery, improves mental focus, and aids in injury prevention and recovery. The use of nutrition strategies to influence HRV is novel and current evidence is scarce in regards to nutritional effects on HRV, specifically in athletes. Current research suggests that achieving energy balance and decreasing body fat in overweight/obese individuals has positive effects on the vagal component of HRV indices. Proper hydration, fruit and vegetable intake, a moderate carbohydrate diet, omega-3 fatty acid supplementation/intake also seem to have positive effects on HRV indices. Certain individual supplements have been studied in regards to HRV including casein hydrolysate, amaranth oil, and bovine colostrum. Caffeine seems to have the opposite effect on HRV indices, increasing sympathetic modulation while decreasing parasympathetic modulation. Much more research needs to be done in regard to potential nutritional influences on HRV so that sport dietitians feel confident in the methods currently used to assess athlete readiness and determining what types of nutrition strategies may be used to further improve the performance of an athlete.

Doctor of Philosophy / Human Nutrition / Edgar Chambers IV / Understanding “why people eat what they eat” is important for improving the lives of people around the world by helping provide industrial and social solutions for people so that they may have greater pleasure and health from the foods they choose. The objectives of the research were to investigate motivations behind everyday meals and choices of different food groups using three different approaches incorporating two psychological perspectives: top-down and bottom-up. The first approach was the Eating Motivation Survey (TEMS) targeting the specific choices of foods and beverages people consumed at specific eating events (breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner, and late-night snack). The second approach was the Food Choice Map (FCM) technique to explore motivations for individual food choices for all eating within a typical week. These two approaches employed the bottom-up process. The last approach used TEMS to investigate food choice directly for six eating occasions, without information about what were eaten specifically. This procedure demonstrated a top-down process because people first thought about their eating as a whole and then read through all TEMS scales to find the motivations that they consider "appropriate" for their answers. The first surveys were completed by 198 participants. The FCM interview was conducted on 100 respondents and the same respondents also participated in the last approach. Data were analyzed by Correspondence Analysis. Liking was the strongest motivation that drove people’s food choice. In addition, need and hunger, habits, price, and convenience were the other main motivations for breakfast, lunch, and dinner while health and weight control were found to be the main driving factors for mid-morning and mid-afternoon snacking. Late-night snacks were linked to pleasure and visual appeal. For dinner, people also were motivated most by variety seeking and traditional eating. Different food groups were also chosen with different motivations. Grain, pasta, meats and poultry were linked to convenience, variety seeking, traditional eating, and price while nuts, seeds, eggs and dairy were associated with need and hunger, health, and weight control. Findings from this project advanced and reinforced the knowledge about food choice and encouraged investigating food choice from different perspectives.

Doctor of Philosophy / Department of Human Nutrition / Brian Lindshield / Fortified blended foods (FBFs), in particular, corn-soybean blend (CSB), are food aid commodities widely used in infant and young children supplementary feeding programs. A United States Agency for International Development (USAID) Food Aid Quality Review report recommended developing novel FBFs using local alternative commodities such as sorghum and improving the nutritional quality of FBFs using extrusion processing. Extruded sorghum-cowpea, sorghum-soy and corn-soy FBFs were developed and compared with the non-extruded FBFs corn-soy blend 13 (CSB13) and corn-soy blend plus (CSB+) using the in-vitro digestion/Caco-2 cell model. Dry FBFs’ iron and vitamin A content ranged from 8.0 to 31.8 mg/100g and 0.54 to 1.67 mg/100g, respectively. Following in-vitro digestion, bioavailable iron and vitamin A levels were determined by measuring Caco-2 cell ferritin and vitamin A levels in response to 12-hour and 4-hour treatments, respectively, with aqueous fractions collected from digested FBFs. Most extruded FBFs’ aqueous fraction iron levels were 2- to 7-fold higher (p<0.05) than CSB13 and CSB+. However, Caco-2 cell ferritin and vitamin A levels were not significantly different among FBFs. These results suggest that consumption of newly developed extruded sorghum-cowpea, sorghum-soy and corn-soy FBFs will result in bioavailable iron and vitamin A levels comparable to traditional non-extruded CSB13 and CSB+. Thus, extruded sorghum-cowpea FBF may be a suitable alternative to corn-soybean based FBFs. Saw palmetto supplements are one of the most commonly consumed products by men with prostate cancer and/or benign prostatic hyperplasia (BPH). Some studies have found significant improvements in BPH with saw palmetto supplementation, whereas others found no benefits. The variation in the efficacy in these trials may be a result of differences in the putative active components, fatty acids and phytosterols, of the saw palmetto supplements. We quantified fatty acids and phytosterols in 20 commercially available liquid, powder, dried berry, and tincture saw palmetto supplements. Liquid saw palmetto supplements contained significantly higher (p<0.05) concentrations of total fatty acids (908.5 mg/g), individual fatty acids, total phytosterols (2.04 mg/g), and individual phytosterols, than the other supplement categories. Our findings suggest that liquid saw palmetto supplements may be the best choice for individuals who want to take a saw palmetto supplement.