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Aspects Of Some Compacted Campground Ameliorating Practices, Keith Foster
Aspects Of Some Compacted Campground Ameliorating Practices, Keith Foster
Electronic Theses and Dissertations
The purpose of this study was to determine if the direct mechanical manipulation of compacted campground soils, with and without the addition of organic materials and the planting of grasses, had any long lasting effect on the amelioration of these deteriorated campsites. An attempt was also made to determine the natural recovery time for East Texas sandy loam soils using the campground closure method. Closure or partial (seasonal) closure of campsites reduced compaction to an acceptable level in three years. Roto-tilling alone was the least effective treatment. Roto-tilling and the addition of bark or chips to maintain the loose soil …
Characterization Of Cell-Cell Interactions In Normal And Tw32 Homozygous Preimplantation Mouse Embryos, Phyllis M. Johnson
Characterization Of Cell-Cell Interactions In Normal And Tw32 Homozygous Preimplantation Mouse Embryos, Phyllis M. Johnson
Electronic Theses and Dissertations
Immediate objectives of the following studies were to characterize and compare normal versus lethal mutant (tW32/tW32) cellular interactions during preimplantation mouse development. Principal experimental methods used included embryo culture and microscopy. Control and mutant embryos were analyzed in vitro to identify chronological events and phenotypic characteristics of tW32 homozygotes. Cell-cell associations of uncompacted and compacted 8-cell control (ICR) embryos were analyzed by quantitative electron microscopy. Lastly, light microscopic analyses were performed on control and mutant (tW32/tW32) morulae.
Growth, Reproduction And Blood Characteristics Of Hereford Females, Harold R. King
Growth, Reproduction And Blood Characteristics Of Hereford Females, Harold R. King
Electronic Theses and Dissertations
The objective of this experiment was to measure the effects of level of wintering nutrition and pasture treatment upon growth and reproduction of Hereford heifers from weaning to 4 1/2 years of age. Levels of certain blood constituents were determined at periodic intervals throughout the study as additional indicators of adequacy in intake for some major nutrients and for measures of general health of the animals. Data pertaining to weight and feed are reported in the English system, even though the metric system was used in the Review of Literature section. This was considered desirable in view of present common …
Purine-Thiamine Anabolism During Cellular Morphogenesis In Myxococcus Xanthus, Wen-Cherng Tsai
Purine-Thiamine Anabolism During Cellular Morphogenesis In Myxococcus Xanthus, Wen-Cherng Tsai
Electronic Theses and Dissertations
Purine-thiamine anabolism during cellular morphogenesis in Myxococcus xanthus was investigated. One of the approaches was to test vegetative and myxospore (2.5 h and 8 h) extracts of M. xanthus CW-2 for their ability to synthesize the second de novo intermediate, 5'-phosphoribosylglycinamide, from beginning precursors either by way of phosphoribosyl-pyrophosphate amidotransferase (EC 2.4.2.14) or ribose-5-phosphate aminotransferase. Results indicate the presence of both the amido- and aminotransferases in both types of extracts, and both enzymes appear to be present at about the same level (per milligram of protein) in vegetative cells, myxospores (2.5 h and 8 h), and in a bacterial prototype, …
Drip And Sprinkler Irrigation Of Carrots And Onions, James D. Melstad
Drip And Sprinkler Irrigation Of Carrots And Onions, James D. Melstad
Electronic Theses and Dissertations
Many specialty crops, especially vegetables, are shallow rooted and sensitive to periods of moisture stress. This makes irrigation of vegetables necessary to their production in South Dakota since summer rainfall is normally both inadequate and undependable. A study was initiated in conjunction with the South Dakota Agricultural Experiment Station and the Water Resources Institute to evaluate irrigation of specialty crops in eastern South Dakota. Drop and sprinkler irrigation were utilized for the irrigation of two specialty crops presently grown in South Dakota, carrots and onions. The study was initiated with the following objectives: 1. To compare carrots and onion yields …
Free Fatty Acids Associated With Induced Rancidity In Cream And Butter, John Alan Anderson
Free Fatty Acids Associated With Induced Rancidity In Cream And Butter, John Alan Anderson
Electronic Theses and Dissertations
One of the most significant problems in the dairy industry today is the flavor defect known as rancidity. This defect has been recognized for some time, but recent trends in milk handling have increased the problem of rancidity. Recently the dairy industry on the farm has changed to the increased use of pipeline milkers and bulk handling of milk. Processing plants are becoming larger and more centralized, resulting in more movement over longer distances for the raw product. These changes result in increased foaming and agitation of the milk, contributing to the rancidity problem. The butter industry has changed. Butter …
Mathematical Models Of Postweaning Growth, Feed Intake And Carcass Composition Of Beef Cattle, Hoon Song
Mathematical Models Of Postweaning Growth, Feed Intake And Carcass Composition Of Beef Cattle, Hoon Song
Electronic Theses and Dissertations
A computer model was developed to evaluate the energetic efficiency of postweaning beef production of various biological types of cattle fed rations with different energy densities. In Section I, a mathematical model was developed to estimate voluntary feed intake for growing cattle from weaning to slaughter. The mathematical model included effects of differences in energy density and crude fiber content of the ration and in breed and degree of maturity of cattle on feed intake. When gastrointestinal tract distension controlled feed consumption, the primary factors determining feed intake were (1) rate of excretion of digesta, (2) rate of digestion, (3) …
Physiologic And Embryologic Studies Of The Yellow (Ay/A) Mouse, Gerald R. Cizadlo
Physiologic And Embryologic Studies Of The Yellow (Ay/A) Mouse, Gerald R. Cizadlo
Electronic Theses and Dissertations
Mice heterozygous for the dominant AY gene have a yellow coat plus an altered metabolism which results in diverse physiologic characteristics including a greatly increased amount of carcass fat, a longer body and tail length, slightly more muscle mass, increased feed efficiency, increased susceptibility to spontaneous and induced tumor growth, and reproductive inefficiency in females. Homozygous AY animals die in utero. The mutation produces a lesion which is potentially valuable as an investigative· tool for the study of physiologic mechanisms and relationships of diverse metabolic pathways. Several experiments were performed to gain information concerning the AY effect. Rate of oxygen …
Detection Of Antibiotic Residues In Bovine Milk, Mark Edward Johnson
Detection Of Antibiotic Residues In Bovine Milk, Mark Edward Johnson
Electronic Theses and Dissertations
Under the Food, Drug, and Cosmetic Act antibiotics are considered as ·adulterants in milk and milk products. Cultured dairy products cannot be made with milk containing small concentrations -of antibiotics. Also, minute quantities of antibiotics cause allergic reactions in some people. Penicillin is the most common antibiotic to which people are allergic, and penicillin is also the most commonly used antibiotic in the treatment of infections in bovines. Antibiotics, whether injected intravenously or intramuscularly, or infused into the udder of the cow, can be secreted into the milk. It is for this reason that withdrawal times for milk from cows …
Intake And Digestibility Of Brown-Midrib Corn Silage By Lactating Dairy Cows, James Allen Rook
Intake And Digestibility Of Brown-Midrib Corn Silage By Lactating Dairy Cows, James Allen Rook
Electronic Theses and Dissertations
Two short-term trials evaluated brown-midrib-3 (bm3) mutant (low lignin) corn silage for early lactation Holstein cows. In trial 1, five cows per group were individually fed a ration of silage and grain (60:40 ratio, dry matter basis) from week 2 through 8 of lactation. Lignin percentages for bm3 and normal silages were 4.9 and 6.4. Cattle fed the bm3 ration consumed 19% more total dry matter as percent of body weight than cows fed normal. Digestibilities of dry matter, cell-wall contents, acid detergent fiber, and energy were 3 to percentage units higher for the bm3 …
A Study Of Milk Composition In South Dakota, Jeng-Jung Yee
A Study Of Milk Composition In South Dakota, Jeng-Jung Yee
Electronic Theses and Dissertations
The composition of cow's milk, including both the fat and solids-not-fat (SNF) content, is known to vary over rather broad ranges. Breed and individuality of the cow are the major factors influencing this, but many other factors are known to exert their influence. However, it has generally been observed that compensation or complementing occurs when the milk of cows is mixed together; so that the composition of milk from a herd will tend toward averages or norms. This effect usually is even more marked as the milk from two or more herds is commingled. Payment for milk on the basis …
Heterospermic Insemination In Swine, Donald G. Levis
Heterospermic Insemination In Swine, Donald G. Levis
Electronic Theses and Dissertations
The studies report herein were conducted to evaluate (1) if there is a difference in pregnancy rate and litter size in swine between heterospermic and homospermic inseminations, (2) the effect of mixing various fresh cm n components involving spermatozoa in the sperm-rich fraction, seminal plasma from the centrifuged post-sperm fraction and Beltsville Ll extender on oxygen consumption, pH, motility and percent dead spermatozoa and (3) the effect of storage (54 hours) on oxygen consumption, pH, motility and percent dead spermatozoa in the various combinations. One Hampshire and one Yorkshire boar were used in the pregnancy rate and litter size study.