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Articles 2941 - 2970 of 3160
Full-Text Articles in Life Sciences
Performance Of A Diurnally Tracking Solar Energy-Intensifier, Calvin E. Siegel
Performance Of A Diurnally Tracking Solar Energy-Intensifier, Calvin E. Siegel
Electronic Theses and Dissertations
The United States agricultural system provides numerous opportunities in which solar energy can be utilized. Low to moderate temperature rise collectors can provide a large percentage of the energy requirements normally met by using high quality fossil fuels. As world demand for food production increases due to a growing population, alternative sources of energy need to be developed and applied as substitutes for these increasingly scarce fossil fuels. Agriculture offers practical advantages for the use of solar heat energy because there exists sufficient area for solar collectors and a wide range of temperature applications on most farmsteads. Demand for energy …
The Influence Of Isotonic And Isokinetic Weight Training On Vertical Jumping Proficiency, Jeffrey Thomas Spielman
The Influence Of Isotonic And Isokinetic Weight Training On Vertical Jumping Proficiency, Jeffrey Thomas Spielman
Electronic Theses and Dissertations
The purpose of this study was to determine the influence of isotonic and isokinetic weight training on vertical jumping proficiency as measured by a modified vertical jump. The subjects were college students enrolled in the Fitness and Lifetime Activities Program at South Dakota State University in Brookings, South Dakota. Isotonic and isokinetic training were assigned to the two experimental groups with the third group serving as controls. Training for the experimental groups consisted of isotonic circuit training on a Universal weight machine and isokinetic training on a Leaper machine. Data analysis included a reliability and reproducibility assessment, and a one-way …
The Effects Of Added Dry Whey On Yield And Acceptability Of Cheddar Cheese, James M. Wingfield
The Effects Of Added Dry Whey On Yield And Acceptability Of Cheddar Cheese, James M. Wingfield
Electronic Theses and Dissertations
Cheese production and sales are a major part of the U.S. dairy industry. Total hard cheese sales have increased 60% in the past 10 yr. Per capita consumption of cheese for the same period has risen from 2.81 kilograms (kg) to 4.03 kg for a 43% increase. In response to greater consumer demand the amount of milk utilized in cheese production has increased markedly during the past quarter century rising from the low of 10% of annual milk production in 1950 to 24% in 1976. This recent increase in cheese production emphasizes the importance of achieving maximum yields of cheese …
Water And Nitrogen Husbandry For Irrigated Corn In Central South Dakota, Stanley Eugene Papendick
Water And Nitrogen Husbandry For Irrigated Corn In Central South Dakota, Stanley Eugene Papendick
Electronic Theses and Dissertations
The purpose of this study was to evaluate the effects of supplemental water and nitrogen on corn yields. Central South Dakota was chosen as the location for this study because of its existing irrigation and the limited research data available from that part of the state. The objectives were: (1) to determine corn yield response to various water regimes, (2) to determine corn yield response to nitrogen applications, and (3) to determine corn yield response to nitrogen application methods.
Effects Of Strain On Response Of Laying Hens To Low Protein Diets And Amino Acid Supplements, Ali B. Kashani
Effects Of Strain On Response Of Laying Hens To Low Protein Diets And Amino Acid Supplements, Ali B. Kashani
Electronic Theses and Dissertations
Corn is by far the most widely used cereal grain in the United States for poultry feeding. In addition to its high energy content, corn provides adequate amounts of the essential fatty acids for maximum rates of growth and egg production. Palatability and ample xanthophyll and provitamin A contents of fresh corn are some o the other contributing factors for its popularity in livestock feeding. The most serious limitation in the nutritional value of corn as well as other cereal grains lies in the fact that they are low in both quantity and quality of protein. It has been a …
Blood Gases And Certain Energy Metabolite Concentrations In Ammonia Intoxicated Sheep, George E. Romkema
Blood Gases And Certain Energy Metabolite Concentrations In Ammonia Intoxicated Sheep, George E. Romkema
Electronic Theses and Dissertations
The objectives of this study were to measure the changes occurring in certain blood parameters during acute ammonia intoxication. It was hoped that these changes would reflect and thereby provide insight into the effects of acute ammonia intoxication on metabolic processes. Blood pH, p02, and pC02 were measured in order to observe possible metabolic disturbances as reflected in the acid-base balance. Glucose was measured due to its importance as a basic energy source and metabolic intermediate. Volatile fatty acids were measured because they serve as an important energy source in ruminants. Non-esterified fatty acids and triglycerides were …
Discharge Measurement And Energy Efficiency Evaluation Of Irrigation Pumping Plants, Bruce A. Jennings
Discharge Measurement And Energy Efficiency Evaluation Of Irrigation Pumping Plants, Bruce A. Jennings
Electronic Theses and Dissertations
No information has been available regarding efficiencies of electric irrigation pumping plants in South Dakota. Pumping plant discharge, a key parameter in the calculation of pumping plant efficiency, is often difficult to measure in the field. A project was initiated at South Dakota State University in 1976 to investigate field pumping plant efficiencies. The following objectives were established for the project. 1. To investigate various methods of measuring irrigation pumping plant discharge. 2. To develop a suitable field procedure for determining electric irrigation pumping plant efficiency. 3. To measure energy efficiency of selected electric irrigation pumping plants in South Dakota.
Methods Of Analysis Of Yield From Antecedent Winter Water, Charles Gregg Carlson
Methods Of Analysis Of Yield From Antecedent Winter Water, Charles Gregg Carlson
Electronic Theses and Dissertations
This investigation is an evaluation of methods of analysis of water conserved during off-season periods and evaluation of the effect on the subsequent crop. Energy and water shortages during the midsummer peak irrigation season have forced farmers to consider the possibility of irrigation at times other than peak growth stages as an alternative practice. Dryland farmers are interested in the benefit of water conserving cultural practices such as summer fallow and snow trapping. To evaluate the benefit of these off-season practices, a yield function based upon water availability is necessary. In order to better understand the effects of off-season irrigation …
A Study Of The Macrobenthic Community In Lake Cochrane, South Dakota, David R. German
A Study Of The Macrobenthic Community In Lake Cochrane, South Dakota, David R. German
Electronic Theses and Dissertations
As part of a continuing study of the biological community of Lake Cochrane, South Dakota, a quantitative survey of the macroscopic bottom fauna was made between the early part of April, 1976 and December, 1976. It was hoped that such a study could provide baseline data for an understanding of the interactions that occur between benthic organisms and other biological components of the lake system. The lake's primary productivity and phytoplankton and zooplankton standing crops have previously been studied by Haertel (1972, 1976) and Steinberg (1972). When this study was being conducted, sediment control dams were being built on three …
Deterioration Of Eggshell Quality And Calcium Metabolism In Laying Hens, Chang Won Kang
Deterioration Of Eggshell Quality And Calcium Metabolism In Laying Hens, Chang Won Kang
Electronic Theses and Dissertations
The present study was undertaken to: (1) develop a reliable method of measuring eggshell quality, (2) determine whether diet alterations that cause a somewhat reduced rate of egg production could influence shell quality, and (3) determine whether certain biochemical parameters involved in calcium metabolism are related to shell quality.
Fatty Liver-Hemorrhagic Syndrome (Flhs) In Caged Laying Hens, Richard A. Nelson
Fatty Liver-Hemorrhagic Syndrome (Flhs) In Caged Laying Hens, Richard A. Nelson
Electronic Theses and Dissertations
A series of eleven experiments was conducted with caged laying hens to study the effects of diet and strain on production and fat accumulation in the liver. In Experiments 1 to 4, a normal ad libitum feeding regime was used, while in Experiments 5 to 11, a force-feeding technique was used as a procedure to increase the incidence of FLHS. Four commercial hybrid strains and a straightbred SCWL (Regional Control) strain were utilized in this study. Choline supplementation at 1500 mg/kg of diet increased egg production from 1 to 11% while decreasing total liver lipid as much as 50%. Supplementation …
The Age And Fertility Of Lignite Strip Mine Spoils From The Darco Mine, Harrison County, Texas, Reagan Cook
The Age And Fertility Of Lignite Strip Mine Spoils From The Darco Mine, Harrison County, Texas, Reagan Cook
Electronic Theses and Dissertations
Field observation of lignite strip mine spoils from the Darco mine near Marshall, Texas, revealed that gray spoil materials of various ages were devoid of vegetation. Within the same sites, spoil materials which were non-gray supported several conditions of revegetation. Analysis of spoil materials from this mine was undertaken to determine if spoils were differentiated on a chemical basis. Gray materials appear to have greater mineral sources of zinc, iron, and sulfate than non-gray spoils, and greater concentrations of zinc, calcium, magnesium, and potassium at all sites. Further, older spoils (17 to 31 years of age) have mean pH values …
Use Of Lignite Fly Ash As A Soil Amendment, Thomas Victor Brown
Use Of Lignite Fly Ash As A Soil Amendment, Thomas Victor Brown
Electronic Theses and Dissertations
One-year-old loblolly pine (Pinus taeda L.) seedlings were grown in a greenhouse in potted mixtures of two Texas lignite fly ashes and a Troup sand, Sacul sandy loam, and a sandy clay loam strip-mine spoil. Mixtures contained 0, 25, 50, 75 and 100 percent fly ash. After six months, soil fly ash mixtures were analyzed for N, P, Ca, Mg, K, Na, Mn, Zn, pH, cation-exchange capacity, percent base saturation, and texture. Needle and root tissue analyses were performed on both live and dead seedlings. Survival and height growth were both adversely affected by fly ash amendments. Nearly all seedlings …
The Effects Of Prescribed Burning On Nutrient Content Of Selected Understory Species In An East Texas Loblolly-Shortleaf Pine Stand, Kelly Bell
Electronic Theses and Dissertations
The objectives of this study were to determine whether prescribed burning affected nutrient levels in leaves and twigs of six species and whether there were differences in response between leaves and twigs. Backfire and headfire treatments were used to determine differences between burning techniques. Samples were collected in October, 1974. The burn was in March, 1975 and post-burn sampling was in June, 1975, September, 1975, and June, 1976. Leaf and twig tissue were analyzed for contents of protein, calcium, potassium, and phosphorus and then subjected to statistical analysis. No difference was found between burning techniques. Protein and phosphorus increased and …
A Comparison Of Cottage Cheese Yields Using Culture And Direct Acidification, David Edward Satterness
A Comparison Of Cottage Cheese Yields Using Culture And Direct Acidification, David Edward Satterness
Electronic Theses and Dissertations
Commercial production of cottage cheese constitutes a significant portion of the total fluid milk utilization in the U.S. Since 1955, yearly per capita consumption of cottage .cheese has steadily increased from 1. 77 kg (3.9 lb) to a high of 2.45 kg (5.4 lb) in 1971 and 1972 (101, 122). A relatively sharp increase in the price of milk solids-not-fat depressed the yearly per capita consumption of cottage cheese to 2. 14 kg (4. 7 lb) in 1974 and 1975 (121). A gradual recovery from this depression was experienced in 1976 with the yearly per capita consumption increasing from 2.10 …
Influence Of Season On Immunoglobulin Absorption And Status In Young Calves, Lynn Maureen Boyd
Influence Of Season On Immunoglobulin Absorption And Status In Young Calves, Lynn Maureen Boyd
Electronic Theses and Dissertations
A high rate of calf mortality can represent a major economic loss to the dairy farmer. Despite increased knowledge in calf rearing, mortality rates of 10 to as high as 25% are not uncommon. The loss of heifer calves alone cost dairymen an estimated $81 million in 1975. This figure does not include the additional costs of extra labor, medication and veterinary expenses, and the loss of genetic potential. The most critical period for calf survival is the first 2 to 3 wk of life. During this time, the calf depends upon colostral immunoglobulins absorbed during the first 24 h …
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 …
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 …
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 …
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 …
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) …
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 …
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, …
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 …
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 …
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.
Percent Accuracy By Crown Closure Classes Of Woodland Stands Mapped From Skylab-4 Photography And Landsat-1 Imagery, Roger Dale Goldsmith
Percent Accuracy By Crown Closure Classes Of Woodland Stands Mapped From Skylab-4 Photography And Landsat-1 Imagery, Roger Dale Goldsmith
Electronic Theses and Dissertations
LANDSAT-l imagery and satellite photography have been utilized for land-use mapping. This study investigated the correlation between woodland stands mapped and their percent crown closure using LANDSAT-l imagery and Skylab-4 photography. On the basis of percent accuracy of crown closure classes mapped or not mapped, Skylab-4 photography proved superior over LANDSAT-l imagery for mapping woodlands
A Comparative Study Of Ribonuclease From Two Winter Barley Cultivars Based Upon Separation, Purification And Partial Characterization Of Rna-Degrading Enzymes, Raymond Sze-Chung Wong
A Comparative Study Of Ribonuclease From Two Winter Barley Cultivars Based Upon Separation, Purification And Partial Characterization Of Rna-Degrading Enzymes, Raymond Sze-Chung Wong
Electronic Theses and Dissertations
The differences in the response to KCl of the RNA-degrading enzymes of two barley cultivars, “Dicktoo” (a hardy type) and "Tennessee Winter” (a non-hardy type), were investigated. Two types of enzymes, ribonuclease (RNase) and nuclease, were separated from crude extracts by disc electrophoresis. The electrophoretic gels were assayed for RNA-degrading activity in the presence and absence of EDTA (EDTA is a nuclease inhibitor). By means of density gradient isoelectric focusing, the nuclease preparation from Tennessee Winter was shown to have an isoelectric point between 5.3 and 5.5, while the nuclease preparation from Dicktoo has three isoelectric points of 4.9, 5.5 …