Four successive experiments were carried out to study the effects of different treatments on the nutritive quality of 4 samples of wheat. The treatments used were autoclaving, freezing, water-soaking, acid-soaking, boiling in water, and combinations of these treatments. Metabolizable energy values of the various samples of treated and untreated wheat were determined using 2-3 weeks old chickens. Nitrogen retention from diets containing the different wheat samples was also measured. Autoclaving of wheat samples for 60 min. at 15 lb pressure markedly increased the nutritive quality of wheat as measured by metabolizable energy values. Freezing at -4°C for 5 days resulted in significant improvement in the metabolizable energy value of the samples of wheat treated in this manner. Water- or acid-soaking did not improve the metabolizable energy values of the wheat samples. The different treatments did not affect the percentage nitrogen retention from diets containing the treated wheat. Prolonged heating (autoclaving for 90 min. and 120 min. at 15 lb pressure) reduced the energy values of wheat as well as the percentage nitrogen retention. / Land and Food Systems, Faculty of / Graduate

The present investigation was conducted to determine the extent to which the effects dietary protein level and amino acid balance have on rate of growth and efficiency of feed conversion can be related to the effects they have upon thyroid activity and tissue respiration. Thyroid activity and body weight were studied in chicks fed diets containing 17.5% and 26% of protein and variously supplemented with amino acids. The basal diets were deficient in methionine and glycine. Growth was stimulated at both protein levels by the addition of methionine or methionine plus glycine to the basal diets. Even when supplemented with amino acids, the low-protein diet was inadequate for maximum growth. Thyroid weight, thyroid weight relative to body weight and I¹³¹ uptake per chick were increased when the protein level was increased from 17.5% to 26% but uptake of I¹³¹ per unit weight of thyroid gland was not affected. Supplementation of the diets with lysine significantly reduced thyroidal uptake of I¹³¹ per chick. Addition of methionine or methionine plus glycine reduced uptake of I¹³¹ per unit weight of thyroid gland. The effect of various levels of dietary lysine, methionine and tryptophan on body weight, efficiency of feed conversion, nitrogen balance and metabolizable energy were studied in relation to concurrent effects of diet on thyroid activity and tissue respiration in chicks. Respiration of liver slices and fiber bundles of skeletal muscle was measured with a Warburg respirometer. Feed and feces were analyzed for nitrogen by the macro Kjeldahl method and for combustible energy with a Parr oxygen bomb calorimeter. Addition of lysine to diets deficient in lysine significantly improved body weight, efficiency of feed utilization, and nitrogen retention in chicks fed the experimental diets. Addition of 0.30% lysine to diets containing 1.09% of lysine improved body weight significantly but had no significant effect on the other parameters mentioned. Addition of methionine to a diet containing 1.39% of lysine improved feed efficiency in birds 17 to 22+ days of age. Amino acid balance had no effect on metabolizable energy. Birds fed lysine deficient diets had lighter thyroids and lower thyroidal uptake of I¹³¹ but had higher uptake of I¹³¹ per mgm. of thyroid gland than those fed diets containing 1.09% or more of lysine. Amino acid balance had no effect on oxygen consumed by muscle tissue, but a deficiency of lysine significantly increased oxygen consumed by liver slices taken from 6 and 8 week old chicks. It is concluded that amino acid composition of dietary protein, as well as the protein level in the diet, affects thyroid activity in the chick. Amino acid imbalance caused by dietary lysine deficiency results in high thyroid activity, low body weight, poor efficiency of feed conversion, and poor nitrogen retention but apparently high respiration of liver slices. Possible shifts in methionine and lysine requirements during the first 25 days after hatch were investigated. It was found that the requirement of the chick for methionine did not change during this time hut that the requirement of the chick for lysine was higher in birds 0 to 20 days of age than in older birds. / Land and Food Systems, Faculty of / Graduate

Sialic acid is the terminal sugar found on most glycoproteins and is crucial in determining serum half-life and immunogenicity on glycoproteins. The scarce supply of sialic acid hinders its advancement in basic research, diagnostic development and therapeutic production. In this work, the recombinant E. coli BRL04 (pBRL89) producing sialic acid was studied by some batch and fed batch runs of high cell density cultivation using a 3-L fermentor. Some cultivation conditions including carbon source, induction time, dissolved oxygen were optimized and different feeding strategies were compared to enhance sialic acid production. The results may be helpful to the further scale-up of sialic acid production and the production of other recombinant proteins by high cell density cultivation of E. coli.

Parenteral nutrition is a therapy that supplies patients with all their nutritional requirements intravenously, thus eliminating the need for oral alimentation. The therapy was first introduced in the United States to hospitalized patients in the late 1960's. The benefit of long-term parenteral nutrition was soon recognized, and a program for ambulatory or home parenteral nutrition (HPN) was developed. In British Columbia, the first HPN patient was begun on such therapy in 1972. Since then, more than 50 British Columbians have received HPN. In March 1986, there were 24 patients on the program. The average annual cost per patient was $29,278 and the total 1986 operating budget was $702,660, not including costs for equipment or hospital training. Up to now, there has been no analytical assessment of the HPN program in B.C. This thesis describes the current home parenteral nutrition situation in B.C. and makes recommendations for its improvement. It looks at overall clinical outcomes (both physiological and psychosocial), at the results with different subgroups of the population, and at the cost of the HPN program in B.C., and also considers the potential of this therapy for children. In Chapter 2, the literature is reviewed and organized to cover a general description of HPN therapy, a summary of the results obtained from a number of academic centers, a review of HPN therapy in childhood and the psychosocial issues of concern to HPN patients. Chapter 3 provides a detailed description of the current HPN situation in B.C. The study methodology is described in Chapter 4 and the results in Chapter 5. The study is a descriptive analysis. Due to the lack of any obvious control group, a comparative evaluation per se was not possible. However, a Seattle study by Robb, reported in 1983, does allow for some comparison. The main sources of data were: 1. A Patient Questionnaire: The questionnaire was modelled on that used by the Seattle group. 23 B.C. patients, either on HPN at the time of questioning, or previously on the therapy, were surveyed. 19 (83%) responded. 2. A Health Professional Questionnaire: This questionnaire was compiled especially for and sent to all known health care workers in B.C. in the HPN field. 19 professionals, including physicians, nurses, pharmacists, dieticians, and administrators, were surveyed. 17 responded for a response rate of 89%. The patient survey provided basic demographic information, a description of HPN therapy received, as well as data on clinical outcomes, both physiological and psychosocial. Results showed that patient age, length of time on HPN, numbers of hours per week devoted to HPN, occupation and place of residence were the most important variables for predicting patient outcomes. Thus, patients that were older, had been on HPN less than one year, or spent more than 80 hours per week preparing and administering HPN solutions, had more physiological complaints and showed interference with more daily activities and personal relationships. Patients who were employed, rated the HPN experience more positively. Overall, patients found the HPN experience to be a positive one, although this was not true for a small group of patients. Data also indicated that B.C. patients achieved physiological results similar to the Seattle group, and to other centers reported in the literature, but appeared to have more interference with daily activities and personal relationships than did patients from the Seattle study. The health professional survey indicated that professionals considered the current situation in B.C. to be good with respect to patient training and the complication rate achieved. However, patient follow-up and the psychosocial support provided to patients were rated only fair to poor. These health care professionals cited problems with the program's organization, the need to standardize service to all patients, and the need to provide patients with pre-mixed solutions. In conclusion, some recommendations are made for improvement in the B.C. HPN program. / Medicine, Faculty of / Population and Public Health (SPPH), School of / Graduate

In this study I examine diet and habitat selection of wood bison (Bison bison athabascae) in the Mackenzie Bison Sanctuary, Northwest Territories. This reintroduced population has increased exponentially since 1963 (r=0.21), and represents the only free-ranging population in existence. A 1987 total count showed at least 1718 animals. The aims of the study were to: 1) determine changes in forage quality and forage quantity amongst the different habitats, 2) determine dietary components on a seasonal basis, 3) determine what biotic and abiotic factors affected habitat selection, and 4) determine home ranges and describe seasonal movement patterns as they relate to the changing distribution of forage. All forages except lichen demonstrated a linear decrease in percent nitrogen concentration and a linear increase in percent indigestible fiber concentration over the growing season. Lichen had consistentent low nitrogen and indigestible fiber concentrations. The ratio of percent nitrogen concentration to percent indigestible fiber concentration (N/ADF) was used as a measure of forage quality. Phalaris arundinacea and willow were better quality forages during summer, while lichen was a better quality forage in fall. The presence of alkaloids and silicates is proposed as the reason P. arundinacea is avoided by bison. Green biomass increased until mid-July, remained high until mid-August and decreased rapidly into September. Wet sedge meadows provided three times more green biomass than willow savannas, however wet sedge meadow forage was of inferior quality and was inaccessible. Forages from willow savannas and willow-aspen habitats were of consistently superior quality until fall when forested habitats provided superior quality forage, the most important of which was lichen. Willow savannas provided the highest available crude protein of all habitats during summer and fall. Wood bison were catholic feeders, and showed pronounced seasonal changes in diet. Sedges, especially Carex atherodes. constituted 96.1-98.8% of the winter diet. During the summer growing season the diet became a more diverse mix of sedge, grass, and willow (Salix spp.). During fall lichen (Cladina mitis) became a major dietary component representing as much as 52.1% of the diet in October. The diet was more diverse at this time of year. There was a pronounced difference between summers in the amount of sedge in the diet. During 1987 the sedge proportion dropped to 30-40% from its 1986 value of 70-90%, while the grass and willow proportions rose. Willow represented as much as 38.7% of the diet during 1987, indicating browse as a viable alternative to monocotyledonous sedges and grasses. A decreased standing crop of sedge in 1987 is proposed as a factor causing the changes in summer forage proportions. Dietary crude was higher in 1986 than 1987. Dietary crude protein levels were intermediate to the levels found in the different forages. Forage availability was the major factor determining habitat selection. Wet sedge meadows were preferred in winter, while willow savannas were preferred in summer. The lack of habitat preference in fall corresponded with the dispersion of animals into forested habitats and the increased use of lichen for forage. Group size and weather conditions had little effect on habitat selection. Snow characteristics affected forage availability. The deeper and denser snow of the 1987-88 winter caused a shift from almost exclusive use of wet sedge meadows to use of both wet sedge meadows and willow savannas. Home ranges were calculated using the minimum convex polygon method. Wood bison home ranges were larger than those of other North American ungulates, ranging in size from 178.5km² to 1441.9km², and far exceeded those predicted by home range-body size relationships. Females had larger home ranges than males. Median daily travel (km/day) was generally greater for females than males. Females travelled more in summer than in fall or winter. Males travelled more during pre-rut and the rut than during post-rut. Forage distribution and availability are proposed as the main determinants of large home range size. Interspecific competition for forage is proposed as a reason for larger home ranges and greater daily travel in females than males. Competition for copulations is proposed as a reason for greater daily travel by males in the pre-rut and rut. / Science, Faculty of / Zoology, Department of / Graduate

This study was designed to provide information on some of the factors affecting voluntary consumption and digestibility of forages by sheep. A wet sieving procedure was used to determine particle size distribution in the reticulo-rumen, omasum and abomasum of sheep fed 100 % prebloom alfalfa or 100 % second-cut Altai wild ryegrass hays or mixtures of these with tall wheatgrass or Altai wild ryegrass straws. The study also compared second-cut Altai wild ryegrass and prebloom alfalfa as components in an all forage diet for sheep. Each diet was fed ad libitum to eight Romanov x Western whiteface wether lambs weighing 22 to 25 kg during the intake and digestibility trials. For the determination of particle size distribution, the animals were slaughtered at 12, 24, 36, and 48 hours after feed removal and the contents of the reticulo-rumen, omasum and abomasum sampled. Five different methods of describing digesta particle size distribution were compared as to their ability to predict voluntary intake and digestibility of the forages by sheep. The best method for expressing particle size distribution in the reticulo-rumen in terms of ability to predict dry matter digestibility (DMD) was the proportion of soluble dry matter in total dry matter (PSDM). A significant (P< 0.05) correlation (r = 0.84) between PSDM and dry matter digestibility, 12 hours after feed removal was obtained. PSDM in omasal digesta 24 hours after feed removal was also highly correlated with DMD and energy digestibility (r = 0.97, 0.91, respectively). Very high correlations were obtained between PSDM in abomasal digesta 24 hours after feed removal and digestibility of cellulose, NDF and ADF (r = 0.99, 0.97 and 0.97 respectively). The proportion of particles less than 1mm to the total particles (PIP) in the reticulo-rumen gave the most consistent correlations with intake of dry matter and energy. Voluntary intake of dry matter by the animals on the alfalfa-based diets were significantly higher (P< 0.05) than those on the second-cut Altai wild ryegrass-based diets. However, the apparent digestibility coefficients of the proximate fractions in the Altai wild ryegrass diets were significantly higher (P< 0.05) than those of diets containing alfalfa. Daily intake of digestible energy by animals on 100 % alfalfa was not significantly different from that of animals on 100 % second-cut Altai wild ryegrass. The difference between their respective combinations with tall wheatgrass and Altai wild ryegrass straws were also not significant. It was concluded that PIP and PSDM are indeces based on biologically significant fractions and may therefore have greater relevance than purely mathematical or statistical descriptions of particle size distribution in digesta. In this regard, the relationship between PSDM and digestibility and, PIP and intake are consistent with published theory and can be used in mathematical models to examine control processes in feed intake, rate of passage and digestion. The study also indicated that second-cut Altai wild ryegrass harvested at the prebloom stage can be used as a substitute for alfalfa in an all-forage diet for winter feeding of sheep. / Land and Food Systems, Faculty of / Graduate

Supplementation with graded levels of threonine to an all barley-lysine diet (0.75% total lysine) improved the daily gain, feed efficiency and carcass quality of growing-finishing pigs. An addition of 0.10% threonine produced the optimum growth response in the experimental animals. No additional improvement was obtained with higher levels of threonine or threonine plus methionine supplementation of the diet. The 0.10% level of threonine supplementation gave performance criteria which were comparable to those obtained with the barley-soybean control diet, except the former diet resulted in significantly higher backfat measurements. Threonine added at levels of 0.15% resulted in higher nitrogen retention than the other barley-lysine-threonine diets. Nitrogen retention on this diet did not differ significantly from the control diet. Barley-amino acid diets resulted in better protein ultilization than barley-soybean control diets. Feeding trials and metabolism trials indicated that methionine was not limiting in barley and that threonine was the second limiting amino acid. Growth trials with weanling rats confirmed the results obtained in the pig nutritional experiments. Rat experiments indicated that no additional beneficial effects were obtained when lysine levels were increased from 0.75% to 0.90% even when supplemented with additional threonine. Results indicated that supplementation with lysine to a total level of 0.75% and threonine at a level of 0.10% resulted in a highly balanced amino acid ratio for rats, and gave growth rates which approached those obtained on the control diet. Supplementation of the barley-lysine diet with 0.20% threonine and all other essential amino acids resulted in growth rates and nitrogen retentions which resembled the results obtained with the control diet. The replacement of the essential amino acid mixture with glycine on an equal nitrogen basis did not result in adequate nitrogen retention or growth rates. / Land and Food Systems, Faculty of / Graduate

Two feeding trials were conducted with 30-week-old single comb white leghorns fed two basal diets containing 8% of hydrogenated coconut oil or safflower oil. These basal diets were fed with or without supplements of \% cholesterol (ch), 2-fo soysterols (st) or in combination (ch+st). Trial 1 was designed to study the sensitivity of laying hens in response to dietary lipid factors and to compare the mode of changes in serum and egg yolk concentrations by weekly determination of their sterol levels during a feeding period with no soysterol supplementation followed by a period with soysterol supplementation. Objectives of trial 2 were to study the effects of dietary lipid factors on the serum and egg yolk levels and to delineate their roles or mechanisms. Changes in egg yolk sterol levels caused by dietary lipid factors were generally parallel to, and preceded by, those in serum sterol levels. This indicated that the egg sterols originated from the circulating labile sterol pool. Safflower oil suppressed and hydrogenated coconut oil elevated the sterol levels in both serum and egg yolk. Cholesterol feeding with dietary safflower oil increased the absorption of cholesterol, resulting in an increase of serum and egg sterol levels as compared to sterol levels of hens fed Hydrogenated coconut oil. Dietary soysterols supplementation resulted in a decrease in both serum and egg yolk sterols which was demonstrated in the presence of dietary cholesterol as well as cholesterol-free treatments. The apparent absorption of cholesterol was not retarded by the simultaneous feeding of cholesterol and soysterols. However, soysterol feeding accelerated the fecal excretion of bile acids and catabolic products of neutral sterols. The apparent absorption of plant sterols was 11%. Absorbability Of plant sterols in laying hens was further supported by detection of these sterols in tissue and egg yolk. The absorption of the plant sterols was, however,. Slightly decreased when cholesterol was fed simultaneously. Cholesterol feeding increased total lipid content in liver and serum, whereas soysterol feeding reduced or diminished lipid accumulation caused by the cholesterol treatment. Both dietary cholesterol and soysterols altered the fatty acid composition of liver, serum and egg yolk lipids by increasing oleic acid and decreasing palmitic and/or stearic acids. These changes were significantly greater upon feeding cholesterol than soysterols. However, the simultaneous feeding of cholesterol with soysterols exerted the least effect on the fatty acid composition in liver. The possibility that soysterols affected biosynthesis and/or oxidative catabolism of fatty acids in the liver of laying hens in a similar fashion as cholesterol was discussed. / Land and Food Systems, Faculty of / Graduate

The biological activity or availability or feedstuff selenium was determined by comparing the effectiveness of the feedstuff with that of dietary sodium selenite in preventing the incidence of exudative diathesis in the chick. The available selenium in ten wheat samples varied from 62 to 178 percent with a mean of 105 percent. The selenium availability in rapeseed meal ranged from 27 to 89 percent with a mean of 61 percent. Selenium metabolism in the chick was investigated by adding graded levels of sodium selenite to the basal selenium deficient diet and comparing the dietary selenium concentration to the selenium concentration in the tissues (l.e. Blood, liver, kidney, and muscle of the chicks). The selenium content in the tissues examined increased proportionately to an increase in dietary selenium supplementation from 0 to 0.2 ppm. Blood and liver selenium concentration remain relatively constant (a slightly increasing plateau) from 0.2 to 1.0 ppm of dietary selenium. Above 1.0 ppm dietary selenium, blood and liver selenium levels increase steadily. These results show that either blood or liver selenium levels represent the selenium status of the bird. A similar response in tissue selenium levels of the chick was observed when selenium was supplied either as sodium selenite Or a feedstuff (brewers yeast). Furthermore, selenium levels birds fed wheat diets were similar to those fed equivalent selenium (sodium selenite) supplied in the basal diet. / Land and Food Systems, Faculty of / Graduate

Two silages were prepared from mature orchardgrass ensiled at 19% dry matter. The additive NutroLac Sila-Aid, containing a dry culture, of lactobacilli, was added to one silage at a rate of 0.5 kg per tonne of fresh herbage, the other silage remained untreated. A wooden stave silo of 40-tonne capacity was filled with each silage. Silage effluent was collected daily for 30 days and the silage temperature was recorded daily for 2.5 months. These two silages comprised the only forage in a two-period crossover design feeding trial. The silages were fed ad libitum (10% feed refusal) and grain was fed at a rate of 1 kg per 3.5 kg milk yield. Twelve Holstein cows in early to mid lactation were subdivided in two groups and allocated to the treated or untreated silage. The cows were fed the assigned forage for a 7-day adjustment period and a 7-week experimental period. The treatments were reversed during a 7-day change-over period and the alternate forage fed for a further 6 weeks. Three cows from each group were assigned to a 7-day digestion trial for total collection of feces and urine during the second last week of each experimental period. The herbage ensiled had the same composition for both silos, the dry matter and protein contents being 19.0 and 14.4% respectively. The treated silage lost almost twice as much effluent compared to the control. Dry matter and protein loss accounted for 2.5 and 4.2% of the ensiled dry matter and protein in the treated silage and 1.5 and 2.3% in the control silage. Peak silage temperatures of 30.3 and 29.1°C for treated and untreated silage were recorded on the ninth day after ensiling. The resulting silage had a dry matter and protein content of 22.8 and 13.2% (treated) and 23.8 and 13.0% (untreated). There was no significant difference (P^.05) between the two treatments with regards to intake, body weight change and milk production. On the average the cows consumed 10.1 kg forage and 8.0 kg grain on a dry matter basis and yielded 2 28.0 kg milk containing 3.2% fat. The animals fed NutroLac silage gained an average of 3.7 kg per period whereas the cows on control silage lost 5.6 kg over the same time. The rumen pH and the acetate/propionate ratio of the ruminal fluid was the same for both treatments, the values being 6.6 and 2.4. The apparent dry matter digestibility of the total ration was significantly higher (P≤.05) for the control silage (70.7%) compared to the treated (69.1). The digestibility of organic matter and protein was not different (P≤.05) between treatments, the average being 7 3.3 and 74.4%. The results from the present experiment tended to be in favour of the control silage and indicated that there was no advantage, and perhaps even a disadvantage, in terms of dry matter digestibility and increased ensiling losses when NutroLac was added to the grass at ensiling time. / Land and Food Systems, Faculty of / Unknown