Introduction: About 80% of those affected by osteoporosis are postmenopausal women. Therefore, identifying beneficial or harmful dietary factors for postmenopausal osteoporosis may have a significant public health impact. Objectives: The overall objective of this thesis was to examine the relations between various dietary factors and bone health in postmenopausal women aged ≥ 45 years using different analytical approaches. Methods: First, the associations between fruit and vegetables (F&V) intake and indicators of bone health were assessed using a systematic review approach. Electronic databases were searched and peer-reviewed observational and interventional studies published in English with F&V intake as a main dietary exposure were included. Data selection, extraction and evaluation of risk of bias were performed independently by two reviewers. Second, the associations between an overall diet quality index (HEI-2005) and its components with bone turnover markers (BTMs) were examined. Third, the relationships between alpha-tocopherol intake, serum alpha- and gamma-tocopherol, two concentration biomarkers of vitamin E intake, and their ratio and BTMs were assessed. For the second and third studies, cross-sectional data from the National Health and Nutrition Examination Survey 1999-2002 were used. Weighted multiple regression models with adjustments for relevant confounders were used to examine the relationship between exposures and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-Telopeptides/Creatinine (uNTx/Cr), a biomarker of bone resorption. Results: There was significant between-study heterogeneity in design, definition and amount of F&V intake, outcomes, analyses and reporting of results in the eight included studies. Overall, cross-sectional and case-control analyses reported protective associations between F&V intake and bone health, whereas interventional and prospective cohort analyses did not. There were no associations between total HEI-2005 scores and BTMs. However, the Milk Group component of HEI-2005 had a significant inverse relationship with uNTx/Cr. Higher serum gamma-tocopherol and lower ratio of serum alpha- to gamma-tocopherol were associated with higher BAP concentrations but had no associations with NTx/Cr concentrations. Conclusions: The results confirm the existing knowledge that a diet with adequate intake of dairy may reduce bone loss. Further research is needed to examine the potential anabolic effects of gamma-tocopherol on bone in postmenopausal women.

Vitamins are readily available in the modern diet due to liberalized fortification and supplementation policies. This research tested the hypothesis that high multi-vitamin intake by Wistar rats during pregnancy leads to the development of obesity and characteristics of the metabolic syndrome in the offspring. Pregnant Wistar rats were fed the AIN-93G diet containing either the recommended (RV) or 10-fold increase (HV) in vitamin content. Pups were weaned to the RV diet (Study 1), an obesogenic liquid diet (Ob, Study 2), low vitamin diets (1/3RV or 1/6RV, Study 3), or a nutrient selection paradigm (NSP) with 10% and 60% casein diets (Study 4). Body weight (BW), food intake (FI), glucose and insulin responses, appetite hormones, abdominal fat pad mass (FPM) and systolic blood pressure (SBP) was measured. Expressions of mRNA for hypothalamic serotonin (5-HT) receptors and proopiomelanocortin (POMC) were measured in Study 4. Males, but not females, born to HV dams had higher post-weaning BW and FI when weaned to the RV or 1/3RV diet, and exhibited components of metabolic syndrome, including higher FPM, hyperglycemia, insulin resistance and elevated SBP compared with those born to RV dams. The Ob diet led to exaggerated weight gain and expressions of components of metabolic syndrome in both sexes born to dams fed the HV diet. Female pups on the 1/6RV diet from HV dams had two-fold higher glucose response and lower insulin response, but no difference in post-weaning BW and daily FI compared to those from RV dams. In contrast to the pups born to HV dams and fed a single diet, those from the HV dams and on the NSP gained less weight and ate less, and had lower hypothalamic mRNA expressions of 5-HT receptors and POMC. In conclusion, high multi-vitamin intake during pregnancy may lead to obesity, and result in a higher risk of developing characteristics of metabolic syndrome in the offspring. However, sex, weaning diet composition, and the presence of diet choice alter the outcomes.

Introduction: About 80% of those affected by osteoporosis are postmenopausal women. Therefore, identifying beneficial or harmful dietary factors for postmenopausal osteoporosis may have a significant public health impact. Objectives: The overall objective of this thesis was to examine the relations between various dietary factors and bone health in postmenopausal women aged ≥ 45 years using different analytical approaches. Methods: First, the associations between fruit and vegetables (F&V) intake and indicators of bone health were assessed using a systematic review approach. Electronic databases were searched and peer-reviewed observational and interventional studies published in English with F&V intake as a main dietary exposure were included. Data selection, extraction and evaluation of risk of bias were performed independently by two reviewers. Second, the associations between an overall diet quality index (HEI-2005) and its components with bone turnover markers (BTMs) were examined. Third, the relationships between alpha-tocopherol intake, serum alpha- and gamma-tocopherol, two concentration biomarkers of vitamin E intake, and their ratio and BTMs were assessed. For the second and third studies, cross-sectional data from the National Health and Nutrition Examination Survey 1999-2002 were used. Weighted multiple regression models with adjustments for relevant confounders were used to examine the relationship between exposures and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-Telopeptides/Creatinine (uNTx/Cr), a biomarker of bone resorption. Results: There was significant between-study heterogeneity in design, definition and amount of F&V intake, outcomes, analyses and reporting of results in the eight included studies. Overall, cross-sectional and case-control analyses reported protective associations between F&V intake and bone health, whereas interventional and prospective cohort analyses did not. There were no associations between total HEI-2005 scores and BTMs. However, the Milk Group component of HEI-2005 had a significant inverse relationship with uNTx/Cr. Higher serum gamma-tocopherol and lower ratio of serum alpha- to gamma-tocopherol were associated with higher BAP concentrations but had no associations with NTx/Cr concentrations. Conclusions: The results confirm the existing knowledge that a diet with adequate intake of dairy may reduce bone loss. Further research is needed to examine the potential anabolic effects of gamma-tocopherol on bone in postmenopausal women.

Vitamins are readily available in the modern diet due to liberalized fortification and supplementation policies. This research tested the hypothesis that high multi-vitamin intake by Wistar rats during pregnancy leads to the development of obesity and characteristics of the metabolic syndrome in the offspring. Pregnant Wistar rats were fed the AIN-93G diet containing either the recommended (RV) or 10-fold increase (HV) in vitamin content. Pups were weaned to the RV diet (Study 1), an obesogenic liquid diet (Ob, Study 2), low vitamin diets (1/3RV or 1/6RV, Study 3), or a nutrient selection paradigm (NSP) with 10% and 60% casein diets (Study 4). Body weight (BW), food intake (FI), glucose and insulin responses, appetite hormones, abdominal fat pad mass (FPM) and systolic blood pressure (SBP) was measured. Expressions of mRNA for hypothalamic serotonin (5-HT) receptors and proopiomelanocortin (POMC) were measured in Study 4. Males, but not females, born to HV dams had higher post-weaning BW and FI when weaned to the RV or 1/3RV diet, and exhibited components of metabolic syndrome, including higher FPM, hyperglycemia, insulin resistance and elevated SBP compared with those born to RV dams. The Ob diet led to exaggerated weight gain and expressions of components of metabolic syndrome in both sexes born to dams fed the HV diet. Female pups on the 1/6RV diet from HV dams had two-fold higher glucose response and lower insulin response, but no difference in post-weaning BW and daily FI compared to those from RV dams. In contrast to the pups born to HV dams and fed a single diet, those from the HV dams and on the NSP gained less weight and ate less, and had lower hypothalamic mRNA expressions of 5-HT receptors and POMC. In conclusion, high multi-vitamin intake during pregnancy may lead to obesity, and result in a higher risk of developing characteristics of metabolic syndrome in the offspring. However, sex, weaning diet composition, and the presence of diet choice alter the outcomes.

The effect of meal-time exposure to food advertisements (FA) on food intake, subjective appetite and caloric compensation was investigated in overweight/obese (OW/OB) and normal weight (NW) boys (study 1) and girls (study 2). In random order, each participant watched either FA or non-food advertisements (NFA) 30 min after consumption of either a non-caloric sweetened control (CON) or a glucose (GLU) drink. Food advertisements increased food intake only in OW/OB girls. The GLU drink reduced food intake in both girls and boys despite no changes in subjective appetite. Food advertisements did not modify the response to the GLU drink in girls and contrary to the hypothesis they magnified the reduction in energy intake following the GLU drink in boys. In conclusion, FA in a TV program during consumption of a pizza meal by NW and OW/OB boys and girls increased food intake only in OW/OB girls and increased caloric compensation for the GLU drink at meal time in boys but not in girls.

The effect of meal-time exposure to food advertisements (FA) on food intake, subjective appetite and caloric compensation was investigated in overweight/obese (OW/OB) and normal weight (NW) boys (study 1) and girls (study 2). In random order, each participant watched either FA or non-food advertisements (NFA) 30 min after consumption of either a non-caloric sweetened control (CON) or a glucose (GLU) drink. Food advertisements increased food intake only in OW/OB girls. The GLU drink reduced food intake in both girls and boys despite no changes in subjective appetite. Food advertisements did not modify the response to the GLU drink in girls and contrary to the hypothesis they magnified the reduction in energy intake following the GLU drink in boys. In conclusion, FA in a TV program during consumption of a pizza meal by NW and OW/OB boys and girls increased food intake only in OW/OB girls and increased caloric compensation for the GLU drink at meal time in boys but not in girls.

Master of Science / Department of Animal Sciences and Industry / John Michael Gonzalez / The objective of this body of work was to examine effects of growth-promoting technologies (GP) on Longissimus lumborum meat tenderness, focusing on alterations of muscle fiber cross-sectional area (CSA) and collagen solubility. Two studies were conducted and analyzed as randomized complete block designs with repeated measures with GP and day of postmortem aging (DOA) as main effects. Treatments consisted of: a control (CON), implant only (IMP), and implant and [beta]-adrenergic agonist (COMBO). The [beta]-adrenergic agonist utilized for the first was zilpaterol hydrochloride, while the second study examined ractopamine hydrochloride. Objective tenderness of strip loin steaks was measured through Warner-Bratzler shear force (WBSF) after 2 (study 2) or 3 (study 1), 7, 14, 21, or 35 d of postmortem aging. Muscle fiber CSA and collagen solubility were analyzed via immunohistochemistry and hydroxyproline content, respectively. For the first study there was a treatment × DOA interaction (P < 0.01) for WBSF. Compared to CON steaks, IMP steaks had greater (P = 0.01) WBSF on d 3, but were similar (P = 0.21) by d 14. The COMBO steaks remained less tender at all-time points (P < 0.04) except d 21 (P = 0.13) when compared to the CON. Growth-promoting treatment increased the CSA of all three muscle fiber types (P < 0.01), but had no effect on collagen solubility measures (P > 0.21). The second study observed no treatment × DOA interaction (P = 0.54) for WBSF, but GP increased (P < 0.01) WBSF across all DOA. Growth-promoting treatment tended to increase the CSA of type I and IIX fibers (P < 0.10), and increased (P < 0.01) type IIA fiber CSA. In agreement with the first study, there was no treatment × DOA interaction or treatment effect on collagen solubility (P > 0.75). The addition of GP to feedlot heifer production increased WBSF of strip loin steaks and fiber CSA, but did not impact collagen characteristics.

Master of Science / Animal Sciences and Industry / Micheal J. Brouk / Study 1 was performed to assess the effect of an evaporative cooling system (ECS) on core body temperature (CBT) and lying times in lactating dairy cows. Respiration rates and rear udder temperatures (T[subscript u]) were also measured. Trial 1 contained 3 environmental treatments while trial 2 contained 2 environmental treatments. Treatments were: OFF (Cyclone fans and fog shut off), FAN (Cyclone fans only, no fog), and FANFOG (Cyclone fans and fog on) and cows exposed to these 3 environments were housed in a bedded pack barn (PACK) equipped with an ECS or a tie-stall barn (TIE). TIE and PACK cows moved between barns every 8 h for milking and both groups moved opposite of each other. Ambient, barn temperature and relative humidity (RH) measurements in addition to vaginal temperatures and lying times were recorded by sensors which took measurements at 1 min intervals. Respiration rates (BPM), for PACK cows during FANFOG were reduced (P < 0.05) when compared to TIE (53 ± 2.0 vs 64 ± 2.0, respectively) in trial 1. Similar results were found in trial 2. Rear udder temperature was measured and found to be decreased (P < 0.05) in PACK cows while housed under FANFOG vs TIE in trial 1. These results could not be repeated in trial 2 because of greater ambient temperatures. Core body temperature (CBT) was reduced during each trial as shown by less time spent above 39.0°C during FANFOG. During trial 2, PACK spent 5.7 and 8.5 h/d less over a CBT of 39.0°C compared to TIE cows. Total daily lying time was tracked and found to increase for cows exposed to the ECS during PACK but no difference between PACK and TIE. In study 2, the same ECS was used but its effects on nonlactating dairy cows were studied. There was a treatment by h interaction for vaginal temperature showing the greatest effects during the afternoon h where FANFOG had numerically decreased CBT vs FAN. FANFOG cows spent reduced time over a CBT of 39.0°C and greater time < 38.0°C. FANFOG cows also had increased lying times of 1.7 h/d compared to FAN.

Doctor of Philosophy / Diagnostic Medicine/Pathobiology / Steven S. Dritz / The overall goal of this dissertation was to evaluate the effects of different amino acid (AA) levels on performance of pigs under commercial conditions. To reach this objective, a total of 12 experiments were conducted. For the sow research, 1,102 highly prolific sows were used to determine the effects of AA and energy intake during late gestation on piglet birth weight and reproductive performance of sows. Weight gain depended on the energy and AA intake levels while sows fed increased amount of energy had increased stillborn rate; however, there was no statistical differences due to energy intake in stillborn rate of gilts. The modest increase in individual piglet birth weight is due to energy rather than AA intake during late gestation. Pre-weaning mortality was reduced in piglets suckling from sows fed high AA diets during late gestation while subsequent reproductive performance was not affected. With recent advances in statistical computing capability, linear and non-linear mixed models were refined to estimate the AA ratio dose-response relationships. Then, 4 experiments using 2,420 wean-to-finish pigs were conducted to validate the methods for estimating the standardized ileal digestible (SID) AA to lysine (AA:Lys) ratio requirement. Subsequently, 7 experiments using 7,562 pigs were conducted to estimate the SID tryptophan (Trp) to Lys and Valine (Val) to Lys ratio requirements of wean-to-finish pigs. In 11- to 20-kg pigs, optimum SID Trp:Lys ranged from 16.6% for maximum mean G:F to 21.2% for ADG. In 30- to 125-kg pigs, optimum SID Trp:Lys ratio ranged from 16.9% for maximum mean G:F to 23.5% for ADG. However, 18% SID Trp:Lys captured 96 and 100% of the maximum mean ADG and G:F for finishing pigs, respectively. In 25- to 45-kg pigs, optimum SID Val:Lys ratio ranged from 72.3% for maximum mean G:F to 74.4% for ADG with 99% of the maximum mean ADG and G:F at approximately 69% and 65% SID Val:Lys ratio, respectively. In conclusion, optimum SID Trp:Lys and Val:Lys were consistently higher for ADG than G:F. This finding is critical for conducting economic evaluations and reference tables such as NRC (2012) should consider presenting requirement values for different response criteria.

Doctor of Philosophy / Department of Animal Sciences and Industry / Christopher D. Reinhardt / Two studies evaluated dry-rolled corn (DRC) manufacturing considerations in feedlot finishing diets. In study 1, feedlots (n = 35) participated in a survey to evaluate dry-rolled corn (DRC) processing practices, processed corn particle size distribution, and fecal starch content in finishing cattle. Average particle size of dry-processed corn, including DRC and hammermill-ground corn across all operations (n = 35) was 4,223 ± 1,265 µm with a range of 1,165 to 6,823 µm. Fecal starch content averaged 19.0 ± 6.5% with a range of 7.0 to 36.6%. Diet composition was evaluated for co-product [27.8 ± 13.4%] roughage concentration [8.9 ± 2.0%] and NDF concentration [19.3 ± 4.3%]. In study 2, cross-bred yearling steers (n = 360; initial BW = 395 ± 33.1 kg) were used to evaluate the effects of dry-rolled corn (DRC) particle size in diets containing 20% (DMB) wet distiller’s grains plus solubles (WDGS) on feedlot performance, carcass characteristics, and starch digestibility. Treatments were Coarse DRC (4,882 µm; COARSE), Medium DRC (3,760 µm; MEDIUM), Fine DRC (2,359 µm; FINE), and Steam-flaked corn (SFC, 0.35 kg/L). Final BW and ADG were not affected by treatment (P > 0.05). Dry matter intake was greater and G:F was lower (P < 0.05) for steers fed DRC vs. SFC. There was a linear decrease (P < 0.05) in DMI in the final 5 weeks on feed with decreasing DRC particle size. Fecal starch decreased (linear, P < 0.01) as DRC particle size decreased. In situ starch disappearance was lower for DRC vs SFC (P < 0.05) and increased linearly (P < 0.05) with decreasing particle size at 8 and 24-h. The final study evaluated steam-flaked corn (SFC) manufacturing practices implemented, equipment utilized, and methods used and parameters targeted to measure flake quality from commercial feedlots (n = 17). Significant variables contributing to the final multiple linear regression model using enzymatic starch availability (Enzymatic) as the dependent variable were: SFC Moisture, cooled flake density (CoolFD), throughput, roll diameter, steam cabinet temperature (Temperature), and temper time (Enzymatic = 19.4476 - (0.6927*SFCMoisture) - (2.1664*CoolFD) - (0.5060*Throughput) + (0.6281*Roll Diameter) + (0.4312*Temperature) – (0.1963*Temper Time; P < 0.15).