This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

The roam objectives of this PhD project were to relate anal~ te solubility in supercritical carbon dioxide via molecular structure and also to investigate the factors that influence the solubility and extraction of analytes in a supercritical fluid extraction (SFE) when using carbon dioxide as the solvent. The polarity of an analyte was selected as the key parameter to developing a means of estimating steroid solubility in supercritical carbon dioxide. Polarity can be estimated by the hydrophobicity term, log P (based on partition coefficients), and also of the solubility parameter, 0,. The use of partition coefficient in conjunction with a calculated solubility parameter was demonstrated as a reasonable means of estimating steroid solubility in supercritical carbon dioxide. Experimental determination of the solubility of several steroid compounds with a range in polarities in supercritical carbon dioxide was carried out in order to correlate solute polarity to the solute solubility. A chromatographic method was also investigated based on capacity factor measurements for the prediction of steroid solubility in supercritical carbon dioxide. The application of supercritical fluid extraction (SFE) \\<ith carbon dioxide and modified carbon dioxide for the extraction of four antifungals from an animal feed matrix has been investigated. The SFE experiments were designed to optimize e:\.1:raction conditions for the extraction of the antifungals from the animal feed to allow for the evaluation of the most significant variables influencing extraction. A method was also developed for the analysis of the SFE animal feed extracts by packed-column supercritical fluid chromatography. The modification of the mobile phase with polar modifier was necessary to elute the antifungals. The procedure provided an alternative separation selectivity to the existing reversed phase high performance liquid chromatography techniques with much shorter analysis time.

Master of Science / Department of Grain Science and Industry / Cassandra Jones / Salmonella contamination in animal food production facilities is a growing concern. The bacteria has been the cause of 40% of pet food recalls in the past 5 years, and there are potential human health implications because pet food is a direct human contact food. A potential method to reduce Salmonella contamination in pet food is through the use of acidifiers and desiccants to destroy and inhibit growth of bacteria. The objective of this thesis was to quantify Salmonella contamination in livestock feed and pet food manufacturing facilities, and propose mitigation measures to mitigate the presence of pathogens in animal food. Therefore, the objective of Experiment 1 was to investigate sources of Salmonella contamination throughout livestock feed (n = 2) and pet food (n = 2) manufacturing facilities on a specific sampling day. Salmonella was present in all four facilities. However, one of the livestock feed manufacturing facilities had more than double the Salmonella-positive locations than all other facilities. This experiment demonstrated that surface type and location should be taken into consideration when controlling Salmonella contamination. In Experiments 2 and 3, the use of a commercial powdered dry acidulant, sodium bisulfate, was studied as a coating of dog kibble to reduce and prevent Salmonella growth over time. The coating reduced Salmonella concentration, and its efficacy was not impacted by altering the bulk density or surface area of the kibble. Experiment 4 was conducted to determine the efficacy of sodium bisulfate added to poultry mash to reduce or prevent Salmonella growth over time. The inclusion of the dry acidulant did not reduce Salmonella concentration; however, storage time reduced Salmonella contamination in poultry feed. In summary, Salmonella contamination exists in manufacturing facilities, but the location and magnitude of contamination differs. Furthermore, sodium bisulfate effectively reduces Salmonella contamination when applied as a pet food coating, but not in poultry feed.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper contains a description of a new technology tracking feed and a discussion of the features which make this feed unique and allow it to perform better than any other comparable feed. Also included in this report are measured primary antenna patterns, measured and estimated phase tracking performance and estimated aperture efficiency. The latter two items were calculated by integrating the measured primary patterns.

A replicated 3 x 3 latin square design (3 periods and 6 rumen fistulated steers) was utilized to investigate the effect of dietary concentrate levels (30, 60 and 90%) on the in situ disappearance of dry matter (ISDMD) and neutral detergent fiber (NDF) and kinetics of fiber digestion of alfalfa hay, wheat straw and steam processed and flaked milo (SPFM). Concentrate levels of 30 and 60% did not affect (P > .05) ISDMD or NDF disappearance from any of the substrates. However, ISDMD and NDF disappearance of all substrates were depressed (P < .05) by the 90% concentrate diet. The degradation of the potentially digestible fiber in these substrates followed first order kinetics at all concentrate levels. Fiber digestion kinetics were not affected (P > .05) by dietary concentrate levels of 30 or 60%. Incubation of substrates in animals receiving the 90% concentrate diet resulted in lower potential extent of digestion (P > .05) and decreased rate of degradation (P > .05) for all substrates. However, digestion was not complete even after incubations of 168-h, and thus, it is possible that the potential extent of digestion was underestimated. For all substrates lag time of digestion appeared to increase in the 90% concentrate diet. However, influx of NDF-like material into the bag during incubation makes the validity of the lag times obtained in situ questionable. Ruminal pH was depressed in animals consuming the 90% concentrate diet and could be at least one of the factors responsible for the decreased (P > .05) fiber digestibility in this diet. Mean ruminal pH of 6.5 (30 and 60% concentrate diets) did not depress (P > .05) fiber digestibility while a mean pH of 6.2 resulted in a lower (P > .05) fiber digestibility in the rumen.

A four-chamber indirect calorimeter was constructed to evaluate energy utilization by laying hens as affected by dietary energy, protein and amino acid levels and by housing temperature. Heat production was measured by indirect calorimetry and metabolizable energy was determined for each diet. Net energetic efficiency was calculated as the slope of the regression of energy balance (metabolizable energy intake - heat production) on metabolizable energy intake. Hens fed diets formulated without protein specifications to provide amino acid levels equivalent to those provided by 14.5 or 16% protein, had higher (P < .05) net energetic efficiencies than hens fed diets formulated with specified protein levels. Addition of 3% animal fat to the higher (16% protein) amino acid diets produced the greatest increases (P < .05) in net efficiency, but decreased (P < .05) efficiency in the lower (14.5% protein) amino acid diet formulated without a protein specification. Metabolizable energy available for production was improved (P < .05) with animal fat additions to all but the diet formulated to the higher (16% protein) amino acid levels. Animal fat, cottonseed oil, corn oil, cod liver oil and safflower oil were used to determine effects of fat source on energy utilization by laying hens at 21.1 C. Higher net efficiencies were obtained for the cottonseed and safflower oil diets (99.1 and 99.8%, respectively) than for the basal diet (90.6%) or the other fat sources (cod liver oil = 86.0%, corn oil = 87.3%, animal fat = 91.1%). Full vs. meal (two 1-hr periods daily) feeding and total sulfur amino acid deficiency effects on energy utilization were evaluated. Meal feeding reduced (P < .05) metabolizable energy available for production while increasing (P < .05) maintenance metabolizable energy requirements. Feeding regime did not reverse the decline (P < .05) in net efficiency (89.2-89.7 to 81.7-82.6%) observed with total sulfur amino acid deficiency. Hens were fed either 7% animal fat or 7% corn oil and maintained at 10, 21.1 and 32.2 C to study effects of fat source and temperature on energy utilization. From 10 to 32.2 C, net energetic efficiency increased from 87.6 to 92.6% with animal fat. Corn oil showed the highest net efficiency (93.9%) at 10 C, while animal fat was highest (92.6%) at 32.2 C. Hens fed animal fat required the most (P < .05) maintenance metabolizable energy and had the highest (P < .05) fasting heat productions at each temperature.

Levels of nitrogen, phosphorus, potassium, calcium, magnesium, zinc, manganese, copper and selenium in grasses grown under rainfed conditions on different soils in the Santa Rita Experimental Range and other areas in southern Arizona were evaluated to determine whether these nutrients are deficient, sufficient or toxic to cattle. In the greenhouse, two grasses grown on five different soils representing four soil orders were fertilized with nitrogen and phosphorus and the uptake of a number of nutrients was determined. For the grasses collected from the field, the nutrient contents generally decreased with time to maturity and the highest levels were attained during August when the grasses were young, and March, the start of the spring growth. The nitrogen and phosphorus contents were lower than the requirement for grazing cattle indicating the need for supplementing protein and phosphorus. The contents of potassium, calcium, zinc, manganese, copper and selenium were adequate for grazing animals. Although the magnesium level in some cases was lower than the requirement, it was considered adequate because its deficiency is now known in warm season grasses. The nutrient contents in the grasses grown on Comoro soils were generally higher than when grown on an adjacent Sonoita soil. Soil analysis revealed no consistent pattern of the levels in these grasses and in Comoro and Sonita soils on which they were grown, except for nitrogen. The nutrient contents in the heads and leaves of two species of grasses were higher than in their stems. The greenhouse experiments showed that the vegetation on the N + P treatment was more vigorous than on the nitrogen treatment and the control, respectively. For the two grasses grown on the five different soils, the nitrogen and magnesium contents mostly were not significantly different between the three treatments, probably due to the dilution effect resulting from the vigorous vegetative growth on the N + P treatment. The phosphorus content in the grasses grown on the N + P treatment was significantly higher than the other two treatments. The nitrogen and phosphorus levels in the soils before and after planting were similar indicating that nitrogen and phosphorus fertilization helped maintain their levels in the soils. Other nutrients in the soils decreased after planting. Most of the nutrients were higher in the surface soils than in the subsurface soils, probably due to the ability of grasses to recycle nutrients from the subsoil.

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