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The purpose of this thesis was to investigate the effects of nutritional supplementation following resistance exercise on protein metabolism, muscle glycogen resynthesis rate, hormonal responses and training status through two unique investigations. The purpose of the first investigation was to determine the effect of post-resistance exercise glucose supplementation upon skeletal muscle fractional synthetic rate (FSR), urinary urea excretion, and whole body and myofibrillar protein degradation (WBPD and MPD, respectively). Eight healthy young males performed unilateral knee extensor resistance exercise(8sets/~1 0reps/~85% 1 RM) such that the non-exercised limb served as a control. They received a carbohydrate (CHO) supplement (1g/kg) or placebo (PL) immediately (t=Oh) and 1 h (t=+1 h) following exercise. FSR was determined for both exercised (EX) and control (CON) limbs by incremental L-[1-13C]leucine enrichment of biopsy samples of vastus lateralis over -10 hours post-exercise. Plasma insulin and glucose were determined at t= -1.5, 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, -10, and -10.5h post-exercise. MPD and WBPD were estimated from 24 hr urinary 3-methylhistidine (3-MH) and L-[1-13C]leucine flux, respectively, and whole body net protein balance was estimated from 24 hr urinary urea excretion. Plasma insulin concentration was greater (p<0.01) at 0.5, 0.75, 1.25, 1.5, 1.75 and 2 h in the CHO compared to PL condition, as was plasma glucose at 0.5 and 0. 75 h (p<0.05). FSR was 36.1% greater in the CHO/EX leg than in the CHO/CON leg (p=N.S.) and 6.3% greater in the PUEX leg than in the PUCON leg(p=N.S.). 3-MH excretion was lower in the CHO (110.43 ± 3.62 J μmol/g creatinine) than PL condition (120.14 ± 5.82)(p<0.05) as was urinary urea nitrogen(8.60 ± 0.66 g/g creat vs. 12.28 ± 1.84)(p<0.05). These findings suggest that CHO supplementation (1g/kg) immediately and 1h following resistance exercise can significantly decrease myofibrillar protein breakdown and urinary urea excretion, thus resulting in a more positive muscle and whole body protein balance. The purpose of the second investigation was to determine the effect of various nutritional supplements upon whole body protein synthesis, urinary urea excretion, and whole body and myofibrillar protein degradation (WBPD and MPD respectively). Ten healthy young male resistance athletes performed a whole body circuit set workout (9 exercises/3 sets/80% 1 Repitition Maximum). Exercises for the legs were performed unilaterally so that the non-exercised leg served as a control They received a carbohydrate (CHO) supplement (1g/kg), a mixed CHO/PRO/FAT supplement (isoenergetic to CHO supplement)(68% CHO, 22% PRO, 10% FAT) or placebo (PL) immediately (t=Oh) and 1 h (t=+1h) following exercise. Immediately following exercise muscle glycogen was significantly lower (p<0.05) in vastus lateralis of the exercised leg than in the control leg immediately post-exercise in all three conditions. Both the CHO and CHO/PRO/FAT supplements resulted in significantly greater increases (p<0.05) in plasma insulin and glucose post-exercise than PL. The CHO and CHO/PRO/FAT also resulted in significantly greater(p<0.05) rates of muscle glycogen resynthesis vs. Placebo. No significant differences were observed between the three conditions for plasma testosterone and cortisol concentration post-exercise. Similarly, no differences were observed between the three conditions for urinary creatinine, and 3-MH and urea nitrogen excretion. Thus, nutritional supplements do not appear to decrease myofibrillar protein degradation as indicated by 3-MH and urea nitrogen excretion in highly trained resistance athletes. Taken together, the two studies suggest that highly trained resistance athletes and untrained individuals both benefit from nutritional supplementation following resistance exercise, but may do so through different mechanisms. / Thesis / Master of Science (MS)

Cattle operations in the Southeastern United States are primarily cow-calf and stocker based and rely heavily on forage. As such, research regarding supplementation strategies that are specific to both the forage cultivars and management strategies that are common in the region are necessary for accurate nutritional recommendations. Additionally, further research is necessary to develop solutions to cope with the negative effects of fescue toxicosis that are common in the region. Therefore, the objectives of this dissertation are to examine supplementation strategies specific to growing cattle as well as to investigate methods of reducing ergot alkaloid intake. Corn gluten feed (CGF) is a common corn co-product that is used to supply supplemental energy and protein. Experiment 1 investigated the effect of supplementing CGF or corn to grazing cattle and found that in grazing situations, growing cattle that are supplemented with CGF have greater average daily gain (ADG) and feed efficiency compared to those supplemented with corn (P  0.03). This improvement in ADG was without changes in subcutaneous fat accretion (P = 0.87), as there were no differences among treatments in fat thickness at the 12th rib (P = 0.54). This improvement in growth and efficiency was thought to be due to differences in the digestibility of fiber in the rumen. Therefore, experiment 2 was designed to investigate the effect of corn or CGF supplementation on apparent total tract nutrient digestibility when cattle are fed a forage-based diet. However, the results from this experiment indicated that there were no changes in neutral detergent fiber digestibility (P > 0.19). In fact, heifers supplemented with corn at 0.25% BW had greater acid detergent fiber digestibility compared with those supplemented with corn at the same level (P = 0.05). Ultimately, this resulted in animals being supplemented with corn tending to have greater organic matter digestibility compared to those supplemented with CGF (P = 0.10). Therefore, the improvement in performance that is observed when grazing cattle are supplemented with CGF compared to corn does not seem to be due to improvements in fiber digestibility. Experiment 3 examined if prolonged storage of ensiled tall fescue would result in the degradation of ergot alkaloids to levels similar to that of hay. Surprisingly, there were no differences among hay or haylage samples for individual or total ergot alkaloids regardless of storage time. Ergovaline concentrations, however, declined after 30 d of storage and were similar throughout the remainder of the storage period. Although no differences were observed among treatments, the reduction of ergovaline concentrations after 30 d of storage indicate that short-term storage may help to reduce the negative effects of fescue toxicosis for the animals consuming it. / Doctor of Philosophy / The Southeastern United States is home to approximately 20% of the country's cattle population and is a major source of feeder cattle that enter the feedlots in the Midwest. The primary nutrient source for cattle in this region is grazeable forage, and production systems in the Southeast are primarily cow/calf or stocker based, with few forage or grain-based finishing operations. Much of the grazeable area is in a portion of the country termed the fescue belt since the primary species of grass is tall fescue. While this species has desirable forage characteristics, it is commonly infected with a fungal endophyte that produces ergot alkaloids that are toxic to livestock. These ergot alkaloids are attributed to billions of dollars of lost revenue and reduced animal welfare. While the forage in the Southeast is of relatively good quality, many producers choose to supplement grazing cattle. This is particularly common during winter months when forage is dormant, and when desired levels of growth exceed what can be provided by forage alone. However, the source of supplemental nutrients can induce changes in the efficiency of forage digestion, and the optimal nutrient source differs when compared to grain-based diets. Therefore, it is important for producers and nutritionists in the Southeast to have access to data relevant to their region of the country. The objectives of this dissertation are to evaluate supplementation strategies relevant for the Southeast, and to evaluate a potential method of mitigating the negative effects of fescue toxicosis in harvested forage. Corn gluten feed has previously been shown to improve performance to a greater extent compared to corn when included in a forage-based diet in a dry-lot setting but has not been investigated in grazing situations. Therefore, we investigated if this effect would be present in grazing situations. Using growing cattle and an automated feeding system, we demonstrated that grazing cattle supplemented with corn gluten feed had greater growth performance compared to those supplemented with corn. To investigate if this was due to differences in nutrient digestibility, we then investigated how total tract digestibility was influenced by supplement type and inclusion level in forage-based diets. However, our results indicated that at relatively small levels of inclusion, total tract digestibility is not impacted by supplement type. To investigate methods to control fescue toxicosis in livestock, we conducted an experiment to determine if ergot alkaloid concentrations in forage harvested as hay and haylage can be reduced through prolonged storage. While there were no differences in concentrations among forage types (hay and haylage), there was a beneficial effect of day for ergovaline concentrations, one of the principal toxins that is present in endophyte-infected tall fescue. This suggests that profits for livestock producers as well as animal welfare can be improved through the short-term storage of harvested tall fescue. Collectively, these experiments demonstrate potential methods for beef producers in the Southeastern U.S. to improve growth in grazing cattle. As researchers continue to improve the understanding of the interaction between grazing livestock and supplementation programs, improved recommendations can be made regarding nutrition programs and ultimately result in a more efficient and profitable operation.

The beef cattle marketing structure imposes stress on calves due to weaning, transport, commingling, and adaptation to new diets, resulting in a weakened immune systems at the height of disease risk, frequently causing bovine respiratory disease. Backgrounding programs facilitate opportunities for calves to overcome stressors by building immunity, and adapting the rumen to high concentrate diets for improved feedlot performance. Four experiments were conducted to compare backgrounding strategies and effects of supplementation frequency performance and the effects of the ruminal environment. In Exp. 1, 48 weaned steers were used to investigate the effects of transportation and supplementation frequency, while in Exp. 2, 36 heifers were used to investigate only supplementation frequency. No differences in gains were observed due to transportation stress or supplementation frequency. Weaning stress resulted in elevated (P < 0.05) creatine kinase and neutrophil:lymphocyte ratios during the first week. In Exp. 3, 48 calves were used to compare the effect of tall fescue type on performance and health. Calves on novel endophyte fescue had higher ADG (P = 0.07) than on endophyte-infected fescue. Experiment 4 investigated the changes in ruminal environment due to supplementation frequency. No differences were observed between supplementation frequencies for ruminal pH, ammonia, or VFA concentration, and DM, or CP digestibility. Therefore, the rumen maintained a hospitable environment to promote bacterial protein synthesis and fiber digestion with every 48 h supplementation. Backgrounding calves with high fiber co-product supplements or on novel endophyte fescue can enhance calf performance. / Master of Science

Undernutrition and oxidative stress in fetal life and infancy may lead to adverse health outcomes in the offspring. We studied nutrition and oxidative parameters in pregnancy and their associations with birth anthropometry and metabolic status in the children. In Matlab in rural Bangladesh, women were randomized to either early (Early) invitation to food supplementation or to start at their own liking (Usual). Women were also allocated to either; 1) 60 mg iron and 400 µg folic acid (Fe60F), 2) multiple micronutrients including 30 mg iron and folic acid (MMS), or 3) 30 mg iron and folic acid (Fe30F). Micronutrients (hemoglobin, iron, zinc, folic acid, vitamin B-12) were assessed in pregnancy week 14, lipid peroxidation in week 14 and 30, and DNA oxidation in week 19. The offspring were assessed for anthropometric measurements at birth and metabolic status at 4.5 years. Micronutrient deficiencies were common with zinc and vitamin B-12 deficiency being most prevalent. Anemia was present in approximately one third of women, however, iron deficiency was uncommon seen in only 2%. Maternal Early food supplementation group resulted in an improved lipid status in the children at 4.5 years compared to Usual food group. Prenatal use of MMS lowered the children’s glucose, insulin, HOMA-IR, and growth factors compared to Fe60F.   Lipid peroxidation in early pregnancy was associated with size at birth and insulin and HOMA-IR levels in the children. Lipid peroxidation in late pregnancy, however, was associated with the children’s lipid status. Both increasing lipid peroxidation and increasing DNA oxidation was associated with decreasing IGF-1 levels.  The beneficial effects of an Early start of food supplementation show that an improved prenatal nutrition may have lasting effects in the offspring and highlights the importance of early timing food supplementation. Use of MMS, however, resulted in lower insulin levels, which, considering the already low level of insulin in these children, may be a cause of concern. MMS also resulted in growth factors indicative of slower growth and further research appears to be needed before scaling up the use of MMS. Oxidative parameters in pregnancy were associated with longer-term outcomes in the offspring, suggesting that oxidative stress may be involved in the development of later metabolic disease.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21806号 / 農博第2319号 / 新制||農||1065(附属図書館) / 学位論文||H31||N5178(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 松井 徹, 教授 久米 新一, 教授 廣岡 博之 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

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