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The amount of urinary conjugated glucuronic acid excreted by a free-living male population and the effect of certain factors, i.e. vegetable, fruit, meat, and charbroiled food intake, tobacco, alcohol, caffeine, and marijuana use, exposure to chemicals and familial cancer incidence, were investigated. Urine was collected for 24 hours from 117 subjects who complied with the collection protocol and analyzed for each subject. Three days of urine were analyzed for a randomly selected subgroup of forty subjects. For the one-day sample, the mean conJugated glucuronic acid excreted was 0.725 mmole/24 hr or 0.0492 mole/mole creatinine. The values for the three-day sample were 0.848 mmole/24 hr or 0.0562 mole/mole creatinine. An analysis of the one-day data revealed a large degree of between-subject (inter-) variability: 47.1%. The corresponding coefficient of variation for the three-day data was 48.2% when three-day averages were compared. The within-subject (intra-) variability for the three-day data corresponded to a coefficient of variation of 29.2%. The large intervariability probably masked any effects of diet, environment, or genetics upon the observed urinary conjugated glucuronic acid excretion. Caffeine use, vegetable, and fruit intake did show differences between low, moderate, and high consumers, although the biological importance of these associations for the small sample sizes is questionable. Further research regarding conjugated glucuronic acid excretion and dietary, environmental, and genetic influences is therefore warranted. / M.S.

The effects of starch and phosphorus (P) source on P partitioning and ruminal phytase activity were evaluated in eight lactating cows (113 DIM). Four cows were ruminaly cannulated. Cows were randomly assigned to treatments in a duplicated 4x4 Latin square with four, 18-d periods. Diets included dry ground corn (DG) or steam flaked corn (SF), with a no supplemental P (low P diet; 0.34% P) or supplemental purified phytic acid (PA; 0.45% P) to provide additional P from an organic source. Total collection of milk, urine, feces, and feed were sampled each period, while rumen fluid was sampled on d 18. Excretion of feces, urine, P, and N was lower in cows fed SF than in cows fed DG. Milk yield was unaffected by diet despite a lower DMI by cows fed SF. Cows fed SF tended to have a higher feed efficiency and lower milk urea nitrogen (MUN) concentration than cows fed DG. Rumen pH was unaffected by diet, but milk fat content was lower for cows fed SF. Milk yield, DMI, and feed efficiency were not affected by PA. Cows fed PA had increased P intake and excretion, but a lower milk P as a percentage of intake compared with cows fed the low P diet. An interaction of starch source and P source was observed for ruminal phytase activity. Altering dietary sources of starch and P offers opportunity to improve P availability and reduce manure nutrient excretion. / Master of Science

A 2-yr field study was conducted to reduce nutrient losses from Virginia dairy farms through nutritional and herd management practices. Ten collaborator herds were identified, all at state DHIA average or better for milk yield and days open. Baseline feed samples and ration information were collected for 2 mo and analyzed for phosphorus (P) and nitrogen (N). Feeds were analyzed monthly, and monthly DHIA milk yield, milk composition, milk urea N (MUN), and reproductive data were recorded. Blood and fecal samples were collected from 25 cows/herd every 3 mo to monitor P excretion and blood urea N. Nutrient balances were developed for each farm for N and P at the start of the study and following ration and management changes. Collaborator herds imported, on average, 290% more N and 320% more P onto the farm than was removed through milk, culled animals, crop sales, or manure sales. By following NRC (1989) recommendations, collaborator farms could reduce N inputs by 21% and P inputs by 45%. Minimizing P in purchased feed, purchased feeds/cow, purchased feeds/ha, and total P input could cause significant reductions in P balance for participating collaborator herds. None of the N variables tested (purchased feed, purchased feed/cow, purchased feed/ha, and total N input) provided significant reductions. / Master of Science

Typescript (photocopy). / Digitized by Kansas Correctional Industries

This thesis describes a project to produce controlled release ketoprofen beads for capsules, both at Oregon State University and in an industrial scale-up operation, that are bioequivalent to the commercial product Oruvail. A bead formulation was produced by layering drug and binders in water onto nonpareil sugar seeds in a spray coating apparatus. Ketoprofen beads manufactured in this manner will immediately release their drug content in either an in vitro or an in vivo environment. Industrially produced beads were non-homogeneous in size. Large beads in a coating batch sweep up a disproportional amount of coating material leading to a thicker coating layer and decreased drug release rates. In order to predict the effects of coating modifications, an equation was developed to accurately predict the coating thickness of any material applied to spherical particles of any size. The equation developed is suggested as a replacement for one that has been in published and cited for over 20 years, but overestimates coating thickness. The bulk of this thesis details the process of altering the drug release characteristics of the beads through application of diffusional and enteric barrier coatings, and testing for bioequivalence with Oruvail through biostudy data gathered from human volunteers. Urinary drug excretion rates were measured as a substitute for timed blood sampling of the subjects. Validity of the substitution was shown. Fed state biostudies involved beads manufactured and coated at Oregon State University. Fasted state biostudies involved beads that were industrially manufactured in a scale-up operation and coated both industrially and at Oregon State University. Deconvolution, a mathematical tool, was used to determine in vivo dissolution rates and the need for further coating modification. Statistical testing using a Two 1-Sided T test was the final arbiter of whether or not bioequivalence was concluded. Bioequivalence was achieved in subjects under a fed state and finally under fasting conditions, as required by the Food and Drug Administration, with drug beads coated with ethylcellulose to slow drug release and overcoated with an enteric bather to retard early drug release. Deconvolved in vivo dissolutions originating from biostudy data were used to develop In Vitro / In Vivo Correlations (IVIVC's). IVIVC's were used to predict in vivo biostudy data from in vitro dissolution results following coating formulation modification. A practical guide for the development and use of an IVIVC was written for pharmaceutics practitioners who have an understanding of pharmacokinetics, but may lack sufficient expertise in pharmacokinetics to develop an IVIVC. / Graduation date: 1998

<p>Successful management of nitrogen (N) excretion is important for sustainable pork production. Two experiments were conducted and their objectives were to study the effect of dietary protein and fibre on N excretion patterns and to relate plasma urea (PU) to urinary N excretion.</p> <p>In the first experiment, three dietary protein contents (high, 197; medium, 169; low, 138 g kg^-1 ) and two levels of fibre (low and high) were tested. Diets (wheat, barley, soybean meal; oat-hulls as the fibre source) were formulated to an equal digestible energy (DE) content (3.25 Meal DE kg^-1) and at least 2.18 g digestible lysine per Meal DE, and were supplemented with Lys, Met, Trp, Thr, Ile, or Val. Pigs (32 ± 3.4 kg; n = 42) were housed in confinement-type metabolism crates for 19 d. On d 10 or 11, catheters were installed by cranial vena cava venipuncture. Daily feeding rates were adjusted to three times maintenance and daily rations were halved to two equal meals. Faeces and urine were collected from d 15 to 19. Five blood samples were collected in two-h intervals on d 16 and 19. Faecal N, urinary N, and total N excretion were reduced linearly with a reduction of dietary protein content (P < 0.001). Reduction was greater for urinary (48%) and total N excretion (40%) than for faecal N (23%) excretion. The ratio of urinary N to faecal N was reduced linearly with a reduction of dietary protein content (P < 0.001). Retention of N (g d^-1) was reduced linearly but N retention as percentage of intake was increased linearly with a reduction of dietary protein content (P < 0.001). Addition of oat hulls did not affect N excretion patterns (P > 0.10). Dietary treatments did not affect average daily gain (ADG) or feed efficiency (P > 0.1 0). Plasma urea increased after feeding, peaked at 4 h and then decreased toward pre-feeding concentrations. A linear relationship of urinary N to PU concentration (R² = 0.66) was observed.</p> <p>In the second experiment, effects of dietary protein content (high, 185; and low, 157 g kg^-1) and fibre sources on N excretion patterns were studied in a 2x3 factorial arrangement. The three fibre sources were control, soybean hulls (SH; 15% ), and sugar beet pulp (SBP; 20%). Diets were formulated to 3.3 Meal DE kg^-1 and 2.4 g digestible Lys per Meal DE, and were supplemented with Lys, Met, Trp, Thr, lie, or Val. Pigs (30.5 ± 3 kg; n = 36) were housed in confinement-type metabolism crates, with restricted access to feed (3 x maintenance DE) from d 1 to 18, and free access to feed from d 19 to 26. Faeces and urine were collected from d 15 to 18 and d 23 to 26, and blood samples on d 17 and 25. With restricted access to feed, faecal N (as % of N intake) was increased 3 percentage units for low compared to high protein content, and increased 4 percentage units for SH and 6.5 percentage units for SBP compared to control (P < 0.05). Urinary N was reduced 5 percentage units for low compared to high protein content, and reduced 9 percentage units for SBP compared to control (P < 0.05). Retention of N (g d^-1) was reduced 12% for low compared to high protein content (17.9 compared to 20.4 g d^-1 ; P < 0.05), and was similar among fibre treatments (P > 0.10). With free access to feed, faecal N (as % of N intake) was increased 2.5 percentage units for low compared to high protein content, and increased 5 percentage units for SH and 9 percentage units for SBP compared to control (P < 0.05). Urinary N was reduced 5 percentage units for low compared to high protein content, and reduced 9 percentage units for SH and 10 percentage units for SBP compared to control (P < 0.05). Retention of N (g d^-1) was similar for dietary protein content (30.5 g d^-1 ; P > 0.10), and reduced for SH (27 g d^-1; P < 0.05) compared to control (31 g d^-1), while was intermediate for SBP (29 g d^-1). A linear relationship of urinary N to PU concentration was observed with both restricted (R² = 0.66) and free access to feed (R²= 0.71).</p> <p>Reduction of dietary protein content is an efficient way to reduce total and urinary N excretion, which may reduce ammonia emission. Inclusion of fibre sources high in fermentable fibre shifted N excretion from urine N to faeces N while fibre sources resistant to fermentation did not have any effects on N excretion patterns. Combined effects of dietary protein content and fibre reduced urinary N excretion further than single effects. Level of feed intake is an important consideration when effectiveness of a nutrient management strategy is studied. Diets with a low protein content and containing synthetic AA should be studied using pigs with free access to feed to verify that N retention is maintained. A linear relationship of urinary N to PU concentration was observed under both restricted and free access to feed indicating that urinary N excretion could be predicted from PU concentration.</p>

<p>Successful management of nitrogen (N) excretion is important for sustainable pork production. Two experiments were conducted and their objectives were to study the effect of dietary protein and fibre on N excretion patterns and to relate plasma urea (PU) to urinary N excretion.</p> <p>In the first experiment, three dietary protein contents (high, 197; medium, 169; low, 138 g kg^-1 ) and two levels of fibre (low and high) were tested. Diets (wheat, barley, soybean meal; oat-hulls as the fibre source) were formulated to an equal digestible energy (DE) content (3.25 Meal DE kg^-1) and at least 2.18 g digestible lysine per Meal DE, and were supplemented with Lys, Met, Trp, Thr, Ile, or Val. Pigs (32 ± 3.4 kg; n = 42) were housed in confinement-type metabolism crates for 19 d. On d 10 or 11, catheters were installed by cranial vena cava venipuncture. Daily feeding rates were adjusted to three times maintenance and daily rations were halved to two equal meals. Faeces and urine were collected from d 15 to 19. Five blood samples were collected in two-h intervals on d 16 and 19. Faecal N, urinary N, and total N excretion were reduced linearly with a reduction of dietary protein content (P < 0.001). Reduction was greater for urinary (48%) and total N excretion (40%) than for faecal N (23%) excretion. The ratio of urinary N to faecal N was reduced linearly with a reduction of dietary protein content (P < 0.001). Retention of N (g d^-1) was reduced linearly but N retention as percentage of intake was increased linearly with a reduction of dietary protein content (P < 0.001). Addition of oat hulls did not affect N excretion patterns (P > 0.10). Dietary treatments did not affect average daily gain (ADG) or feed efficiency (P > 0.1 0). Plasma urea increased after feeding, peaked at 4 h and then decreased toward pre-feeding concentrations. A linear relationship of urinary N to PU concentration (R² = 0.66) was observed.</p> <p>In the second experiment, effects of dietary protein content (high, 185; and low, 157 g kg^-1) and fibre sources on N excretion patterns were studied in a 2x3 factorial arrangement. The three fibre sources were control, soybean hulls (SH; 15% ), and sugar beet pulp (SBP; 20%). Diets were formulated to 3.3 Meal DE kg^-1 and 2.4 g digestible Lys per Meal DE, and were supplemented with Lys, Met, Trp, Thr, lie, or Val. Pigs (30.5 ± 3 kg; n = 36) were housed in confinement-type metabolism crates, with restricted access to feed (3 x maintenance DE) from d 1 to 18, and free access to feed from d 19 to 26. Faeces and urine were collected from d 15 to 18 and d 23 to 26, and blood samples on d 17 and 25. With restricted access to feed, faecal N (as % of N intake) was increased 3 percentage units for low compared to high protein content, and increased 4 percentage units for SH and 6.5 percentage units for SBP compared to control (P < 0.05). Urinary N was reduced 5 percentage units for low compared to high protein content, and reduced 9 percentage units for SBP compared to control (P < 0.05). Retention of N (g d^-1) was reduced 12% for low compared to high protein content (17.9 compared to 20.4 g d^-1 ; P < 0.05), and was similar among fibre treatments (P > 0.10). With free access to feed, faecal N (as % of N intake) was increased 2.5 percentage units for low compared to high protein content, and increased 5 percentage units for SH and 9 percentage units for SBP compared to control (P < 0.05). Urinary N was reduced 5 percentage units for low compared to high protein content, and reduced 9 percentage units for SH and 10 percentage units for SBP compared to control (P < 0.05). Retention of N (g d^-1) was similar for dietary protein content (30.5 g d^-1 ; P > 0.10), and reduced for SH (27 g d^-1; P < 0.05) compared to control (31 g d^-1), while was intermediate for SBP (29 g d^-1). A linear relationship of urinary N to PU concentration was observed with both restricted (R² = 0.66) and free access to feed (R²= 0.71).</p> <p>Reduction of dietary protein content is an efficient way to reduce total and urinary N excretion, which may reduce ammonia emission. Inclusion of fibre sources high in fermentable fibre shifted N excretion from urine N to faeces N while fibre sources resistant to fermentation did not have any effects on N excretion patterns. Combined effects of dietary protein content and fibre reduced urinary N excretion further than single effects. Level of feed intake is an important consideration when effectiveness of a nutrient management strategy is studied. Diets with a low protein content and containing synthetic AA should be studied using pigs with free access to feed to verify that N retention is maintained. A linear relationship of urinary N to PU concentration was observed under both restricted and free access to feed indicating that urinary N excretion could be predicted from PU concentration.</p>

This study investigated the interaction between polychlorinated biphenyls (PCBs) and selenium to explain the mechanism involved that could affect selenium metabolism and its anti-cancer property. PCBs congeners and mixtures were previously found to reduce hepatic Se and Se-dependent glutathione peroxidase activity. I hypothesized that certain PCB congeners affect selenium metabolism in the rat liver resulting in diminished antioxidant capacity of selenoproteins, which could alter the ability of Se to protect against PCBs induced tumor promotion. In the first study, the influence of 3,3,4,4-tetrachlorobiphenyl (PCB 77) on hepatic Se and glutathione peroxidase (GPx1) activity as well as cytochrome P450 1A1 induction was examined by employing a time-course study, which showed that PCB 77 significantly reduced the hepatic selenium level and GPx1 activity and that this effect was influenced by gender. The next study explored how PCB 77 could deplete hepatic selenium by determining selenium concentrations in different tissues, feces and urine. This study demonstrated that PCB-77 decreased hepatic Se by increased excretion of Se in urine but not in feces. Unlike glutathione peroxidase, thioredoxin reductase activity was not affected by PCB 77. The third study investigated the effect of selenium supplementation on the tumor promoting activity of PCB 77 and 2,2,4,4,5,5-hexaclorobiphenyl (PCB 153) using a 2-stage carcinogenesis model. Se supplementation did not diminish the induction of altered hepatic foci by coplanar PCB 77 or ortho-substituted PCB 153. Instead of protection, the number of foci per cubic centimeter and per liver among the PCB-77 treated rats was increased as the selenium dietary level increased. PCB 153 did not show the same selenium dose-response effect; nevertheless, selenium supplementation did not confer protection against foci development. On the other hand, supranutritional selenium reduced the mean focal volume. Supranutritional selenium or PCBs did not affect cell proliferation or thioredoxin reductase activity. Lastly, the use of the Zeeman graphite furnace atomic absorption spectrometry (GFAAS) method and closed microwave digestion technique for selenium determination of biological samples was compared with the neutron activation analysis and fluorometry methods. I found that GFAAS was not as reliable as the other methods.

Bibliography: leaves 183-202 / xxiv, 202 leaves, [46] leaves of plates : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agricultural Biochemistry, Waite Agricultural Research Institute, 1984