Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 80-89). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 80-89). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 112-120). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 112-120). Also available on the Internet.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 18, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Jeffre Firman. Includes bibliographical references.

Experiments were designed to investigate the possibility of using mice as model animals for the evaluation of protein quality, and to compare it with rats under the same conditions. Parameters measured were protein efficiency ratio, net protein ratio, protein digestion and relative protein value. Six sources of protein were tested at three dietary levels for each. Measurements were taken at four different periods of feeding, thus, the effects of dietary level of protein and the length of the feeding period were studied. Results on mouse experiment indicated that the highest PER values were obtained at 6 and 8% levels of dietary protein with significantly lower values when 11% levels were fed. The highest NPR values were obtained at 6% level of dietary protein then declined when 8 or 11% levels were fed. The highest efficiency regarding PER and NPR were obtained when mice were fed for 10 days than when they were fed for 14, 21, or 28 days of experiment. High quality protein sources were needed at lower levels in the diet for shorter periods of time to obtain the maximum efficiency when compared to poor quality sources of protein. Results for protein digestion did not correlate with those of PER, NPR or RPV indicating that protein digestion is a poor measurement. However, PER, NPR, and RPV were highly correlated. Results of rat experiment were in agreement with what was reported in the numerous works for rat bioassay in the literature review. Rate of body weight gain increased with increasing levels of dietary protein and the PER reached a maximum value, then decreased. Values of NPR tended to fall with increasing levels of dietary protein. PER values tended to increase gradually with prolonged period of feeding, then decline. The maximum PER values were obtained when 10% level of dietary protein was fed for a period of 15 days. Likewise mice experiment, PER, NPR, and RPV correlated highly while protein digestion correlated poorly with the other methods used. In general mice appeared to be influenced by the same factors as rats when used for the evaluation of protein quality. Mouse could be used as a model animal for protein quality evaluation with the advantages of small animal size, lower feed intake, shorter period of feeding, plus is highly desirable for experiments involving the use of isotopes or whole carcass analysis. A dietary protein level of 8% for a feeding period of 10 days would be suitable for use with mice instead of a 10% dietary level for a 28 day feeding experiment in rats. Whole eggs could be used as a suitable reference standard protein for mouse bioassay.

Three duodenally cannulated lactating Holstein cows fed cotton-seed meal (CSM), corn gluten meal (CGM) or blood meal (BM) as protein supplement were used in a 3 x 3 Latin Square experiment to determine microbial crude protein (MCP) in duodenal digesta. Diets, formulated to contain 15% crude protein (CP) on a dry matter basis, consited of 60% concentrate, 31% corn silage and 9% alfalfa hay. Chromium oxide was employed as flow marker. Microbial protein fraction of digesta CP (MCP/DCP) was estimated by three microbial markers: ¹⁵N, diaminopimelic acid (DAP) and ribonucleic acid (RNA). The isotopic method gave the most reliable results. Variability was higher with DAP and RNA. Results from RNA were lower (P < .01) and unreasonable. Based on ¹⁵N, MCP/DCP differed among treatments (P < .10) with means of 61.5, 59.4, and 50.0% for CSM, CGM, and BM, respectively, but differences were not significant for absolute amounts of total CP and MCP in duodenal digesta.

The present study was performed to determine if pigs varying in their susceptibility to stress, adapted to a casein-based diet, experience an improvement in biochemical parameters related to stress and behaviour compared to pigs adapted to the traditional western canadian cereal-based swine diet. Experiment 1 involved separating fifty-eight, 8-week old pigs according to genotype with respect to the halothane gene. Within each genotype pigs were divided into 2 groups and assigned to either a control diet or to a diet where most of the protein source was substituted for casein. All animals were adapted to diet for 6 weeks and experienced a weekly blood sampling stressor. Day 1, 14 and 35 of the plasma samples were analyzed for glucose, cortisol, ACTH, insulin, pyridoxal 5$ sp prime$-phosphate (PLP), amino acid concentrations and dopamine-$ beta$-hydroxylase (DBH) activity; metabolic indices known to be responsive to stress. Experiment 2 involved separating fifty-seven, 14-week old pigs in the same manner, then adapting the pigs to their respective diets for a period of 4 weeks. Afterwards, pigs were transferred from their pen to a novel pen-maze situation where they had their behaviour monitored for a period of one hour. Results of these experiments have revealed that (1) the stress susceptible and carrier pigs experienced reduced day 35 plasma glucose, PLP concentrations and DBH activity compared to normal pigs; (2) dietary adaptation to the casein diet resulted in greater day 14 and 35 PLP levels and day 35 essential amino acid lysine, threonine, methionine, tryptophan and arginine concentrations compared to control-adapted pigs; (3) the carrier pigs investigated their surroundings more frequently than the stress susceptible pigs, and the normal pigs engaged in the through-maze behaviour more often than the stress susceptible pigs; and (4) adaptation to the casein diet, compared to the control diet, resulted in fewer displacement-type behaviours such as drinking

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 13, 2008) Vita. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 136-148). Also available on the Internet.