Two experiments were conducted to determine the efficacy of supplemented feedstuffs to improve the performance of cattle consuming fescue-based rations. The objective of the first experiment was to evaluate growth and reproductive characteristics of heifers consuming endophyte-infected (EI) fescue seed with or without sodium bicarbonate supplementation. Forty-eight heifers (8 mo; BW = 268 ± 24 kg) were utilized in a 2 x 2 factorial design. Treatments were either high-EI fescue seed without sodium bicarbonate (E+B-), high-EI fescue seed with sodium bicarbonate supplementation (E+B+), low-EI fescue seed without sodium bicarbonate (E-B-), or low-EI fescue seed with sodium bicarbonate supplementation (E-B+). At d 56, G:F (P= 0.084) and ADG (P = 0.071) tended to be improved for heifers fed E+B+. By d 84 bicarbonate supplementation tended to decrease ADG (P = 0.087). Bicarbonate supplementation ameliorated the negative effects of E+ at 28 d, but by d 84 negatively impacted animal performance. The objective of the second experiment was to determine the energy content of corn gluten feed (CGF) relative to corn in forage-based beef rations. Forty-two steers (13.8 ± 0.4 mo; BW = 382 ± 8 kg) were supplemented with either corn or CGF at 0.15% (L), 0.54% (M) or 0.96% (H) BW for 63 d. Steer ADG was greater for steers supplemented with CGF relative to steers supplemented with corn (P = 0.034). Energy value of CGF relative to corn was calculated by adjusting supplement TDN in the 2016 Nutrient Requirements of Beef Cattle Model. The energy values of CGF relative to corn were 106%, 107%, and 112% for L, M, and H. / Master of Science / Tall fescue is the predominant forage in the southeast United States, and has a symbiotic relationship with an endophytic fungus, providing drought and pest resistance to the plant. However, the fungal endophytes produce toxic ergot alkaloids which can result in decreased performance when cattle consume tall fescue. Performance losses, resulting from the consumption of these ergot alkaloids, are costly and economical strategies to reduce the negative impact of endophyte-infected fescue consumption on animal performance are needed. Previous research indicates that ruminal buffering capacity and nutrient uptake may be impaired in cattle consuming endophyte-infected fescue seed. Providing a dietary buffer is a low-cost strategy that my help to improve nutrient utilization in cattle, resulting in improved animal performance. Aside from reduced performance resulting from the consumption of ergot alkaloids, forage nutrient content can vary throughout the year, resulting in situations where the animals’ nutrient requirements are not met by the forage alone. Historically, corn has been the major energy supplement used, but recent data suggest that co-products of the corn sweetener and ethanol industries have greater energy compared to corn in both feedlot and forage-based beef rations. Supplementing corn gluten feed at low levels may improve performance of cattle consuming forage-based rations without driving up the cost of production. The objective of this thesis is to evaluate two strategies to mitigate the negative effects of endophyte-infected fescue consumption on animal performance. The first experiment was conducted to evaluate the efficacy of sodium bicarbonate to mitigate the negative effects of endophyte-infected fescue on replacement heifers. Heifers were fed a basal corn silage diet. Fescue seed and bicarbonate were supplemented at 1.5 kg/day and 0.25 kg/day, respectively. After a 56 d treatment period, bicarbonate supplementation tended to improve performance of heifers fed endophyte-infected seed with bicarbonate relative to those fed un-infected seed without bicarbonate supplementation. However, by d 84 of the experiment, the benefits of bicarbonate supplementation were no longer observed. More research is needed to understand why the benefits of sodium bicarbonate supplementation were not sustained over the full experimental period. The second experiment was conducted to evaluate the feeding value of corn gluten feed relative to corn when fed to steers consuming a forage-based ration. Steers had free-choice access to fescue hay, and individual hay and supplement intake were recorded daily. Steers supplemented with corn gluten feed had greater average daily gain than steers supplemented corn. This translated to a greater energy value relative to corn for all inclusion levels, exceeding model predictions. These experiments help to shed light on low-cost solutions to improve performance and profitability for fescue forage-based beef production systems.

Abstract available in the Current Developments in Nutrition.

The purpose of this study was to investigate if a low mixed carbohydrate plus moderate protein supplement, provided during endurance exercise, would improve time to exhaustion in comparison to a traditional 6% carbohydrate supplement in female athletes exercising at or below their ventilatory threshold. Fourteen (n = 14) trained female cyclists and triathletes cycled on two separate occasions for three hours at intensities varying between 45% - 70% VO₂max, followed by a ride to exhaustion at an intensity approximating the individual's VT (average 75.06% VO₂max). Supplements (275ml) were provided every 20 min during exercise and were composed of a 3% carbohydrate mixture + 1.2% protein (CHO+PRO) or a 6% carbohydrate-only (CHO). The CHO+PRO treatment contained a mixture of dextrose, maltodextrin, fructose, and whey protein isolate. The CHO treatment was composed of dextrose only. Time to exhaustion (TTE) was significantly greater with CHO+PRO in comparison to CHO (49.94 ± 7.01 vs 42.36 ± 6.21 min, respectively, p < 0.05). Blood glucose was signifcantly lower during the CHO+PRO (4.07 ± 0.12 mmol x L⁻¹) trial compared to CHO (4.47 ± 0.12 mmol x L⁻¹), with treatment x time interactions occurring from 118 minutes of exercise until exhaustion (p < 0.05). Heart rate was significantly lowered in the CHO+PRO treatment during exercise as compared to CHO (p < 0.05). There were no significant differences for other blood measures, ratings of perceived exertion or carbohydrate and fat oxidation between trials. Results from the present study suggest that the addition of a moderate amount of protein to a low mixed carbohydrate supplement improves endurance performance in females above that of a traditional 6% carbohydrate supplement. Improvement in performance occurred despite CHO+PRO containing a lower carbohydrate and caloric content. It is likely the greater performance seen with CHO+PRO was a result of the carbohydrate protein combination and the use of a mixture of carbohydrate sources. / text

Acute respiratory infections (ARI) are a major global cause of morbidity and mortality. Vitamin D deficiency has been reported to associate with susceptibility to ARI and with greater severity and poorer control of asthma and chronic obstructive pulmonary disease (COPD). Clinical trials of vitamin D for the prevention of ARI have yielded heterogeneous results, with some showing protection and others not. This may reflect variation in the frequency of genetic variants influencing response to vitamin D supplementation in different populations. The impact that genetic variation in the vitamin D pathway has on vitamin D status, disease phenotype and response to vitamin D supplementation in prevention of ARI has not been comprehensively investigated. Methods: I conducted: 1. A systematic review and meta-analysis of clinical studies which have investigated vitamin D as a potential therapy for ARI; 2. Three cross-sectional studies (in n=297 adult asthma patients, n=278 COPD patients, and n=272 older adults) to investigate potential environmental determinants (lifestyle and anthropometric) and genetic determinants (35 single nucleotide polymorphisms [SNP] in 11 vitamin D related genes) of serum 25-hydroxyvitamin D concentration (25[OH]D) and clinical phenotype; 3. Three prospective studies investigating the influence of genetic variation in the vitamin D pathway on a) susceptibility to ARI (main effects analysis) and b) efficacy of vitamin D supplementation for the prevention of ARI (interaction analysis). Results: My systematic review identified consistent reports of an inverse association between vitamin D status and risk of ARI in observational studies, and heterogeneous reports from clinical trials. My cross-sectional studies identified a range of classical environmental factors which predict vitamin D status in the three study populations, but did not identify any genetic variants in the vitamin D pathway that associate with vitamin D status. I identified an association between vitamin D deficiency and decreased lung function in COPD patients, but no associations between vitamin D deficiency and asthma phenotype. Finally, my analysis identified a haplotype of 5 single nucleotide polymorphisms in the vitamin D receptor (VDR) gene which significantly modify the effect of vitamin D supplementation on risk of upper respiratory infection in COPD patients. Conclusions: I identified environmental determinants that predict 25(OH)D concentrations in all three study populations, but only found an association between vitamin D deficiency and disease severity in COPD patients. Furthermore, I identified a haplotype in VDR which modifies the effect of vitamin D supplementation in COPD patients to result in a significantly reduced risk of ARI.

This diploma thesis deals with the issue of protein intake in fitness strength sports. Proteins are one of the most important nutrient for strength athletes because muscle mas is made up of about 20% of proteins. Because of athlete's desire for a well-balanced muscular body, they attach proteins a major role and often overstate their significance. Bodybuilding and other strength sports are often associated with extreme protein intake, which can lead to negative health effects (deficiency of some minerals, kidney load, digestive troubles, etc.). The aim of this thesis is to evaluate whether power athletes receive excess, optimum intake or lack of protein according to the current recommendations for sports nutrition. A record sheet for diet intake was used to collect the data. The protein intake of power athletes was calculated in the Nutriservis program and compared with the recommendation according to number of training lessons and the target of the athletes (fat reduction, weight maintenance or muscle growth). The diet of power athletes was also critically evaluated. The results were evaluated by relevant text commentaries and summarized using a graph. The result is that 45% of strength athletes consume excess protein and their intake is higher than 2.0 g protein/kg/day. However, it was also found...

It is highly recommended for women to take multivitamin/mineral supplements during the periconceptional and prenatal periods. Studies have confirmed that taking prenatal multivitamins prevents maternal iron deficiency anemia, and reduces the risk for neural tube defects (NTDs). To date, research aimed at optimizing the use of multivitamins before and during pregnancy has been minimal. My thesis focused on two challenges of periconceptional and prenatal multivitamin supplementation. The first challenge was gastrointestinal (GI) adverse events such as nausea and constipation which may be attributed to iron content and tablet size. Pregnant women are highly susceptible to GI adverse events since 80% experience nausea and vomiting of pregnancy. A prospective, randomized, controlled, open-label study was conducted to investigate whether a low-iron, small-tablet prenatal multivitamin can reduce GI adverse events, and improve supplement tolerability and adherence, relative to a high-iron, small-tablet prenatal multivitamin. We determined that low iron dose did not produce a significant difference, while small tablet size could be considered an important factor. Moreover, our results confirmed that adherence was poor in pregnant women. We were prompted to identify determinants which could predict adherence to prenatal multivitamins. Our retrospective study determined that predictors of adherence are rooted in women’s prior experiences with multivitamin use. The second challenge we addressed was achieving adequate blood folate concentrations for prevention of NTDs. If adherence is poor, standard dosing of 0.4-1 mg folic acid may not produce the blood folate concentrations needed in women prior to conception. We investigated the pharmacokinetics of 5 mg folic acid. Our prospective, parallel, open-labeled study, comparing a single dose of 5 mg to 1.1 mg folic acid, confirmed that folic acid follows linear (proportional) pharmacokinetics. However, our prospective, randomized, controlled, open-labeled, multiple-dose study determined that repeated use of folic acid at these 2 doses followed non-linear pharmacokinetics. Nevertheless, our data confirmed that 5 mg folic acid can produce higher blood folate concentrations, with a faster rate, which can counter the effect of poor adherence. In conclusion, optimal use of prenatal multivitamins requires improvements in supplement tolerability, adherence, and pharmacokinetics which depend on supplement formulations, and individualized assessment and counseling.

Maternal and child undernutrition are a significant problem in the developing world, with serious consequences for human health and socio-economic development. In Cambodia, 55% of children, 43% of women of reproductive age, and 50% of pregnant women are anemic. Current prevention and control practices rely on supplementation with iron pills or large-scale food fortification, neither of which are affordable or feasible in rural Cambodia. In the study areas, 97% of women did not meet their daily iron requirements. The current research focuses on the design and evaluation of an innovative iron supplementation technique. A culturally acceptable, inexpensive and lightweight iron ingot was designed to resemble a fish species considered lucky in Khmer culture. The ingot, referred to as ‘try sabay’ or ‘happy fish’, was designed to supply iron at a slow, steady rate. Iron leaching was observed in water and soup samples prepared with the iron fish when used concurrently with an acidifier. More than 75% of daily iron requirements can be met with regular use. Its use in the common pot of soup or boiled water provides supplementation to the entire family. The effectiveness of the iron fish was investigated in a randomized community trial involving 310 women in rural Cambodia. Blood samples were taken at baseline and every three months thereafter, over a 12-month trial period. Significant increases in hemoglobin concentrations were observed in women allocated an iron fish when compared to controls throughout the study, with an endline difference of 11.6 g/L. Significant improvements in serum ferritin concentration were observed at 9 months (6.9 ng/mL) and endline (30.8 ng/mL) in women who used an iron fish regularly when compared to the control group. Overall, use of the iron fish led to a two-fold reduction in the prevalence of anemia. The supplement was used daily by 94% of the households at the end of the trial. The study highlights the acceptability and effectiveness of a fish-shaped iron ingot as a means of improving dietary iron content. It offers a promising, simple solution to iron deficiency anemia if the project can be scaled-up for use throughout the country. / Canadian Institutes of Health Research, University of Guelph, International Development Research Centre (Canada)

Folate intake in North America has drastically increased over the past decade due to folic acid fortification and widespread supplemental use. The role of folate in breast cancer is highly controversial and the effects of folic acid supplementation on breast cancer patients are currently unknown. An animal study was performed to determine the effects of folic acid supplementation on the progression of the mammary tumors in the DMBA-carcinogen model. Folic acid supplementation was associated with more rapid sentinel tumor progression and with higher sentinel tumor weight, volume, and area, although no clear dose-responsive relationship was observed. Folic acid supplementation was associated with an increased expression of proapoptotic protein PARP and decreased expression of proliferation protein PCNA. These data suggest that folic acid supplementation may promote the progression of established mammary tumors. Whether or not folic acid supplementation may adversely affect the outcome of patients with breast cancer warrants further studies.

Folate intake in North America has drastically increased over the past decade due to folic acid fortification and widespread supplemental use. The role of folate in breast cancer is highly controversial and the effects of folic acid supplementation on breast cancer patients are currently unknown. An animal study was performed to determine the effects of folic acid supplementation on the progression of the mammary tumors in the DMBA-carcinogen model. Folic acid supplementation was associated with more rapid sentinel tumor progression and with higher sentinel tumor weight, volume, and area, although no clear dose-responsive relationship was observed. Folic acid supplementation was associated with an increased expression of proapoptotic protein PARP and decreased expression of proliferation protein PCNA. These data suggest that folic acid supplementation may promote the progression of established mammary tumors. Whether or not folic acid supplementation may adversely affect the outcome of patients with breast cancer warrants further studies.

It is highly recommended for women to take multivitamin/mineral supplements during the periconceptional and prenatal periods. Studies have confirmed that taking prenatal multivitamins prevents maternal iron deficiency anemia, and reduces the risk for neural tube defects (NTDs). To date, research aimed at optimizing the use of multivitamins before and during pregnancy has been minimal. My thesis focused on two challenges of periconceptional and prenatal multivitamin supplementation. The first challenge was gastrointestinal (GI) adverse events such as nausea and constipation which may be attributed to iron content and tablet size. Pregnant women are highly susceptible to GI adverse events since 80% experience nausea and vomiting of pregnancy. A prospective, randomized, controlled, open-label study was conducted to investigate whether a low-iron, small-tablet prenatal multivitamin can reduce GI adverse events, and improve supplement tolerability and adherence, relative to a high-iron, small-tablet prenatal multivitamin. We determined that low iron dose did not produce a significant difference, while small tablet size could be considered an important factor. Moreover, our results confirmed that adherence was poor in pregnant women. We were prompted to identify determinants which could predict adherence to prenatal multivitamins. Our retrospective study determined that predictors of adherence are rooted in women’s prior experiences with multivitamin use. The second challenge we addressed was achieving adequate blood folate concentrations for prevention of NTDs. If adherence is poor, standard dosing of 0.4-1 mg folic acid may not produce the blood folate concentrations needed in women prior to conception. We investigated the pharmacokinetics of 5 mg folic acid. Our prospective, parallel, open-labeled study, comparing a single dose of 5 mg to 1.1 mg folic acid, confirmed that folic acid follows linear (proportional) pharmacokinetics. However, our prospective, randomized, controlled, open-labeled, multiple-dose study determined that repeated use of folic acid at these 2 doses followed non-linear pharmacokinetics. Nevertheless, our data confirmed that 5 mg folic acid can produce higher blood folate concentrations, with a faster rate, which can counter the effect of poor adherence. In conclusion, optimal use of prenatal multivitamins requires improvements in supplement tolerability, adherence, and pharmacokinetics which depend on supplement formulations, and individualized assessment and counseling.