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Full-Text Articles in Life Sciences

Biology And Ecology Of False Wireworms In South Dakota (Coleoptera: Tenebrionidae), Carrol Otto Calkins Jan 1973

Biology And Ecology Of False Wireworms In South Dakota (Coleoptera: Tenebrionidae), Carrol Otto Calkins

Electronic Theses and Dissertations

False wireworms were important pests of wheat on the Great Plains during the early 20th century. Until recently, they were of little importance; however, they are now occasionally appearing in damaging proportions. The purpose of studying the biological and ecological aspects of these insects in South Dakota was to understand the factors responsible for their demise and the circumstances that could affect the recurrence of damaging populations. The more common species of false wireworms found in South Dakota during this study were Eleodes suturalis (Say), E. opaca (Say), E. hispilabris (Say), E. tricostata (Say), E. extricata (Say), E. obsoleta (Say), …

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The Development And Testing Of A Fire Simulator Exercise, Don A. Clymer Aug 1972

The Development And Testing Of A Fire Simulator Exercise, Don A. Clymer

Electronic Theses and Dissertations

A forest fire simulation exercise was developed for the purpose of supplementing forest fire instruction, presenting students with decision-making situations encountered on forest fires, and introducing them to the fire simulator at Stephen F. Austin State University. The final exercise was developed after preliminary work and development of a more simple exercise. The problems with equipment, recruitment of simulator personnel, and the development and execution of the simulator exercises are discussed. Scheduling adequate time for practice, and providing adequate personnel training were found to be the major obstacles in simulator use. Future fire simulator use at SFA will be dependent …

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The Biology Of Geomylichus Gaomydis N. Sp. (Acari: Listrophoridae) From The Plains Pocket Gopher, Geomys B. Bursarius (Shaw), Charles Campbell Coffman Jan 1972

The Biology Of Geomylichus Gaomydis N. Sp. (Acari: Listrophoridae) From The Plains Pocket Gopher, Geomys B. Bursarius (Shaw), Charles Campbell Coffman

Electronic Theses and Dissertations

Geomylichus geomydis n. sp. is an obligate ectoparasite and associated with it on Geomys b. bursarius were large numbers of four other major ectoparasite species and small numbers of eight miscellaneous acarine taxa. Descriptions and measurements of life cycle stages of Geomylichus geomydis n. sp. are given. Geographical and host distribution records are also included. Seasonal population numbers of Geomylichus geomydis n. sp. and the other four major ectoparasite species were analyzed. Infestation rates for G. geomydis n. sp. were determined for seasons of the year and sexes and ages of the host. A least-squares analysis of variance was used …

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Recognizability And Reproducibility Of Airphoto Interpreted Landscape Units, Robert Dean Heil Jan 1972

Recognizability And Reproducibility Of Airphoto Interpreted Landscape Units, Robert Dean Heil

Electronic Theses and Dissertations

A physiographic terrain analysis study using the principles of airphoto interpretation was made: (1) to determine the internal homogeneity of airphoto interpreted mapping units, (2) to determine the variability in characteristics among different occurrences of the same mapping unit, and (3) to determine if the units differentiated were sufficiently different to warrant discrimination. The study was conducted in Sedgewick County, Colorado. The study area was comprised of four distinctly different land forms [sic]: a major river and its associated floodplain and terraces; a level to nearly level loamy upland plain; a level to sloping sandy upland plain; and steeply sloping, …

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Carboxymethylcellulose As A Carrier For Follicle Stimulating Hormone In The Female Rat And Bovine, C. Leroy Johnson Jan 1972

Carboxymethylcellulose As A Carrier For Follicle Stimulating Hormone In The Female Rat And Bovine, C. Leroy Johnson

Electronic Theses and Dissertations

A series of biological assays were conducted to compare physiological saline (PSS) and carboxymethylcellulose (CMC) as carriers for follicle stimulating hormone (FSH) and to determine the optimum ratio of FSH to CMC. Constant individual dosages of 0.5 mg FSH were injected into a total of 384 immature female rats in four experiments. Treatments included single injections of FSH in PSS, FSH in 1 percent CMC at ratios (mg FSH: ml CMC) OF 1:3, 1:2, 1:1, 2:1, 3:1, 5:1 and FSH in 2 percent CMC at a ratio of 1:1. Parameters of primary and secondary response were ovarian and uterine weight, …

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Evidence For The Presence Of Two Nucleases In Barley Tissue And The Influence Of Genotype On Their Properties, Clay G. Johnson Jan 1972

Evidence For The Presence Of Two Nucleases In Barley Tissue And The Influence Of Genotype On Their Properties, Clay G. Johnson

Electronic Theses and Dissertations

Several lines of evidence have shown that genetic variability exists within the barley species (Hordeum vulgare L.) with respect to the kinetics and specificity of yeast ribonucleic acid degradation. Initial efforts demonstrated that ribonuclease (RNase), in the crude soluble protein fraction from the cultivar Dicktoo, was inhibited by KC1 and phosphate. RNase activity was enhanced if heated to 60 C for short periods. In contrast, RNase in the crude soluble protein of the cultivar Tennessee Winter showed no altered response by either KC1 or phosphate. Maximal RNase activity was at pH 5.0 for extracts of both cultivars (0.16 M KC1), …

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Estimation Of N Availability And No3-N Movement In Soils, Raymond Charles Ward Jan 1972

Estimation Of N Availability And No3-N Movement In Soils, Raymond Charles Ward

Electronic Theses and Dissertations

Objectives of this study were: (a) to evaluate several N soil tests that are used to estimate soil N availability, and (b) to measure the distribution of inorganic N in the soil profile after an application of fertilizer N. Small grain yield response from an application of 17, 34, or 67 kg N/ha was used as the parameter of N availability. These parameters were related to 23 independent variables by use of a step wise multiple regression program. Nitrogen soil tests and climatic factors (rainfall and temperature) were the independent variables involved in the analysis. Nitrogen soil tests included were …

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The Effect Of Allopurinol (4-Hydroxypyrazolo(3,4-D) Pyrimidine) On Uric Acrid Metabolism In Differential Grasshoppers (Melanoplus Differentialis) And Armyworms (Pseudoletia Unipuncta), Henry C. Schroeder, Jr. Jan 1972

The Effect Of Allopurinol (4-Hydroxypyrazolo(3,4-D) Pyrimidine) On Uric Acrid Metabolism In Differential Grasshoppers (Melanoplus Differentialis) And Armyworms (Pseudoletia Unipuncta), Henry C. Schroeder, Jr.

Electronic Theses and Dissertations

Allopurinol, a potent inhibitor of xanthine oxidase in humans, was incorporated in the diets of differential grasshopper nymphs and adults and armyworm larvae. Uric acid contents of whole body homogenates decreased by highly significant rates. Feces uric acid decreased by highly significant rates in grasshopper nymphs and adults. Allopurinol also caused highly significant increases in mortality and inhibition of metamorphosis in study insects. These effects were not reversible by the addition of purine and pyrimidine bases, inosine, oxypurines, or uric acid. The effects were reversed by discontinuing application of allopurinol. Crude xanthine oxidase, assayed by measuring the reduction of NAD …

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Effects Of Manganese Chloride On Gravid Gilts And Newborn Pigs, Dale A. Wade Jan 1972

Effects Of Manganese Chloride On Gravid Gilts And Newborn Pigs, Dale A. Wade

Electronic Theses and Dissertations

Excessive dietary manganese in young mammals has depressed hemoglobin levels, red blood cell synthesis and growth in some investigations, while in other research these were increased. Toxic levels, mode of action and specific physiological effects are unknown although manganese, cobalt and iron appear to compete for absorption mechanisms. Manganese functions in enzyme systems and in carbohydrate and lipid metabolism, is present in red cells and plasma and may be incorporated into the hemoglobin molecule. Gravid gilts were utilized in these investigations since piglet anemia is an economic problem and manganese effects in swine have not been fully defined. Gilt rations …

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An Incrementally Distributed Mathematical Model Of A Watershed, Charles Arnold Onstad Jan 1972

An Incrementally Distributed Mathematical Model Of A Watershed, Charles Arnold Onstad

Electronic Theses and Dissertations

The utilization of distributed input parameters enables hydrologists to more adequately cope with watershed management problems. A distributed system aids in evaluating alternative solutions designed to alleviate a problem situation. As a result, the objectives of this study were (1) to develop a hydrological framework delineating the surf ace configuration of a watershed to consider parameter distribution; (2) to develop a model of hydrologic performance of a watershed using existing techniques and amenable to the physical framework; and (3) to demonstrate the versatility of the model using hypothetical data. The model versatility was demonstrated by showing the effects of different …

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Amino Acid Supplementation Of Low Protein Layer Diets, Harlal Choudhury Jan 1972

Amino Acid Supplementation Of Low Protein Layer Diets, Harlal Choudhury

Electronic Theses and Dissertations

Experiments were conducted at the South Dakota State University Poultry Research Center to study the effects of amino acid supplementation of low protein diets on performance of laying type hens. Hans, housed in 8-inch cages, were fed at 24 weeks of age typical 16% protein corn-soy diets diluted with glucose to 10.8% protein and supplemented with 0.15% DL-methionine, 0.19% L-lysine and 0.04% DL-tryptophan. After about 20 weeks of depletion, supplements of 0.05 and 0.1% DL-threonine and DL-valine and 0.1% DL-isoleucine alone and in all combinations were fed for a further period of 16 weeks using a factorial design. Individual supplements …

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Sephadex G-25 And Charcoal Separation Of Mouse Growth Inhibitors In Soybeans From Trypsin Inhibitors, Larry James Tidemann Jan 1972

Sephadex G-25 And Charcoal Separation Of Mouse Growth Inhibitors In Soybeans From Trypsin Inhibitors, Larry James Tidemann

Electronic Theses and Dissertations

Rising costs have changes man’s ideals and eating habits. Plant ingredients, because of their relatively low costs, have been increasingly used as a substitute for animal proteins. If these plant ingredients could be directly utilized by man, this would be a more efficient use of energy and nutrients. One plant source currently used in such a manner is soybeans, which is a prime source of protein for human and livestock nutrition. However, soybeans contain several factors that are detrimental to man and livestock. Heating of soybeans counteracts these factors, since the undesirable factors are heat labile. However, heat alters the …

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Nitrate Movement In Freezing Or Frozen Soils, Donald G. Moore Jan 1972

Nitrate Movement In Freezing Or Frozen Soils, Donald G. Moore

Electronic Theses and Dissertations

Nitrate movement in freezing and frozen soils was studied in both disturbed and undisturbed soils by laboratory and field investigations. Thermoelectric cooling plates were placed in insulated freezing boxes. Soil cores placed in the freezing boxes were stored, frozen, or thawed at a specific temperature or temperature gradient. Field plots and soils columns reset into the field environment were used to observe migration of either fall- or winter-applied nitrate. Movement of surface applied nitrate was caused by passage of a freezing front through either saturated or unsaturated sand or saturated Vienna loam. The nitrate movement due to freezing was greater …

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The Effect Of Level Of Dietary Protein On The Growth And Carcass Characteristics Of Growing-Finishing Swine Fed To A Heavy Weight, Keith E. Gilster Jan 1972

The Effect Of Level Of Dietary Protein On The Growth And Carcass Characteristics Of Growing-Finishing Swine Fed To A Heavy Weight, Keith E. Gilster

Electronic Theses and Dissertations

Two hundred sixteen crossbred barrows and 96 crossbred gilts were used in a series of three experiments to determine the effect of dietary protein level during three different growth periods on growth am quantitative and qualitative carcass traits of the growing-finishing pig. Pigs were fed from approximately 20 to 113 kilograms. Corn-soybean meal diets fortified with recommended levels of vitamins, minerals and an antibiotic were fed. Pigs fed 20, 18 or 16% protein diets from weights of 20 to 45 kg gained both significantly faster and more efficiently than pigs fed diets of 12% protein. Feeding a low (12%) protein …

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Tolerance Studies To Wheat Streak Mosaic Virus In Winter And Spring Wheats, Fazal Rahman Jan 1972

Tolerance Studies To Wheat Streak Mosaic Virus In Winter And Spring Wheats, Fazal Rahman

Electronic Theses and Dissertations

Thirty-five winter and fourteen spring wheat varieties were evaluated for their reaction to wheat streak mosaic virus during 1969-1970 and 1970-1971. Plants were mechanically inoculated and the effects of virus were measured, relative to the control plots, in regards to seed yield, protein percentage, plant height, test weight, 1000-seed weight, number of tillers per plant, number of heads per tiller, number of seeds per head, and number of plants in the 2-foot subplot. Varieties were compared visually for their susceptibility to the virus in terms of percentage infection and severity of symptoms. Seed yield, plant height, test weight, 1000-seed weight, …

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Bionomics Of Mallophaga Of Sharp-Tailed Grouse In South Dakota, Major L. Boddicker Jan 1972

Bionomics Of Mallophaga Of Sharp-Tailed Grouse In South Dakota, Major L. Boddicker

Electronic Theses and Dissertations

The ecologies of chewing lice (Insecta:Mallophaga) which parasitize sharp-tailed grouse, Pedioecetes phasianellus, were studied in southwestern South Dakota from 1964 to 1967. Five hundred twenty-eight hens, cocks and chicks were collected and examined for louse damage. Louse populations were monitored each month from December, 1964, to September, 1967. Five louse species which infested grouse in the study area were Goniodes nebraskensis Carriker, Amyrsidea megalosoma Overgaard, Lagopoecus perplexus Kellogg and Chapman, Goniocotes chrysocephalus and Lipeurus maculosis Clay. Goniodes nebraskensis fed on feather parts and skin debris and was found to have seasonally fluctuating populations. Cocks carried peak populations of 250 lice/host …

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The Role Of Rainfall Impact And Surface Flow In Soil Detachment And Transport, Robert Alan Young Jan 1972

The Role Of Rainfall Impact And Surface Flow In Soil Detachment And Transport, Robert Alan Young

Electronic Theses and Dissertations

Soil erosion caused by rainfall is a very complex physical process. To evaluate the mechanism of erosion so that an assessment can be made of the extent to which it may be controlled necessarily begins with an understanding of the basic fundamental factors involved. The purpose of this study involves the development of an insight of the relative importance of the roles played by various contributors to the erosion process. Particular emphasis is placed on the contribution of rainfall detached soil to total soil loss. Three soil types, Barnes loam, Crofton silt loam and Central sandy loam, were prepared with …

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Physiological Regulation Of Cyclic Flowering In Flax, Aurora Salazar Hovland Jan 1972

Physiological Regulation Of Cyclic Flowering In Flax, Aurora Salazar Hovland

Electronic Theses and Dissertations

The flowering pattern of flax (Linum usitatissimum, L.) is cyclic in nature with periods of blossoming separated by periods of rest. To study the regulation of flowering cycles, four experiments were conducted. The first two dealt with nutritional aspects of cyclic flowering by imposing environmental stresses which conceivably might regulate flowering pattern nutritionally. The third and fourth experiments dealt with regulation from hormonal systems and included in vitro regulation of bud growth by growth regulators as well as characterization of endogenous hormonal systems by fluorimetry and bioassays. In the first experiment, the effects of light intensity, temperature, nitrogen and defoliation …

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The Effects Of Chlorpropamide In Diets Of Gravid Gilts On Embryo Survival, Fetal Weight And Fetal And Dam Blood Sugar Levels, Duane E. Wachholz Jan 1972

The Effects Of Chlorpropamide In Diets Of Gravid Gilts On Embryo Survival, Fetal Weight And Fetal And Dam Blood Sugar Levels, Duane E. Wachholz

Electronic Theses and Dissertations

Seventy-six primiparous, crossbred gilts averaging approximately 125 to 135 kg were used in a series of two experiments to determine the effects of chlorpropamide upon reproductive and blood criteria. The drug, fed at the rate of 1000 ppm (1816 mg per day) and 3000 ppm (5448 mg per day), was included in a 14% protein basal diet from the day following breeding until gilts were sacrificed after 60 or 95 days of gestation. The 515 fetuses collected from these gilts were used to obtain information about the effects of chlorpropamide on individual weights and blood glucose and fructose levels. Data …

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The Effect Of Pulp Mill Effluents On The Carbon Dioxide Evolution Of Three East Texas Soils, John C. Morris Aug 1971

The Effect Of Pulp Mill Effluents On The Carbon Dioxide Evolution Of Three East Texas Soils, John C. Morris

Electronic Theses and Dissertations

Two pulp mill effluents, NaOH extraction water from the pulp bleaching process and water from the chlorination step of the pulp bleaching process, were applied to jars containing three East Texas soils. Carbon dioxide evolution was then measured with an infrared gas analyzer to determine the effect of the effluents on the respiration of soil microorganisms. The relationship between effluent treatments was not statistically significant, though detrimental effects were observed in the heavier soil. Irrigation of clays and clay loams with the effluent is not recommended. Irrigation of sandy soils should be possible if there is no danger of sub-surface …

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Responses Of Rumen Microflora To Whey Products Added To High-Grain Low-Roughage Rations, Virgil L. Metzger Jan 1971

Responses Of Rumen Microflora To Whey Products Added To High-Grain Low-Roughage Rations, Virgil L. Metzger

Electronic Theses and Dissertations

Many factors present in livestock feeds affect the numbers and types of protozoa and bacteria in the rumen. A small particle size of feed and a fast rate of passage of the feed through the ruminant decreases protozoal numbers. Full feeding of a concentrate ration and an acid pH in the rumen also tend to reduce protozoa numbers. Bacteria numbers tend to increase as the protozoa numbers decrease. Knowledge of rumen microflora population changes on different rations is lacking. It is known that restricted-roughage rations will generally cause lower protozoal numbers. Since whey is an available source of lactose and …

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The Lipid Composition Of Milk As Affected By High Grain-Limited Roughage Rations Containing Whey Products, Roger Charles Peper Jan 1971

The Lipid Composition Of Milk As Affected By High Grain-Limited Roughage Rations Containing Whey Products, Roger Charles Peper

Electronic Theses and Dissertations

Certain rations fed to lactating dairy cows appear to have a dramatic influence on the lipid composition of milk fat produced. A high grain ration fed with a limited amount of roughage tends to cause a depression in milk fat production while at the same time changing the milk fat composition. There have been various attempts to alleviate the depression in milk fat. Minerals used in the ration seem to slightly relieve the milk fat depression caused by high grain rations. One drawback has been lower milk production due to a decline in concentrate consumption. Whey products added to a …

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A Study Of The Endogenous Electron Donors For Nitrogen Fixation By Cell-Free Extracts Of Klebsiella Pneumoniae M5al (Aerobacter Aerogenes M5al), Elisabeth Yi-Jan Wu Jan 1971

A Study Of The Endogenous Electron Donors For Nitrogen Fixation By Cell-Free Extracts Of Klebsiella Pneumoniae M5al (Aerobacter Aerogenes M5al), Elisabeth Yi-Jan Wu

Electronic Theses and Dissertations

Biological nitrogen fixation, the mechanism of the enzymatic conversion of the inert nitrogen gas into amino acids in the cytoplasm of the microorganism has puzzled many scientists for decades. The recent discovery of some free-living nitrogen-fixing bacteria has encouraged the investigation of this mechanism. A big step taken in the rapid elucidation of this mechanism was the first reproducible cell-free nitrogen-fixing system from Clostridium pasteurianum successfully obtained by Carnahan et al. (9) in 1960. In the following decade, reproducible cell-free systems were demonstrated with the strict aerobe, Azotobacter vinelandii (4), facultative anaerobic Bacillus polymyxa (16) and Klebsiella pneumoniae (31) and …

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A Two Year Study Of Potential Resistance In The Adult Western Corn Rootworm In South Dakota, John M. Wirtz Jan 1971

A Two Year Study Of Potential Resistance In The Adult Western Corn Rootworm In South Dakota, John M. Wirtz

Electronic Theses and Dissertations

The western corn rootworm Diabrotica virgifera Le Conte, and the northern corn rootworm Diabrotica longicornis Say, are major pests affecting corn in South Dakota. Jones (1968) considered the rootworm the number one corn pest in South Dakota and estimated that the rootworm caused fifty percent of all insect damage done to corn. Prior to 1961 the northern corn rootworm was the predominant species causing damage in South Dakota. The western corn rootworm is presently the predominant species (Nearman, 1968). Cultural and chemical control methods have been used to control corn rootworms in the past with varying degrees of success. Crop …

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Evaluation Of Orally Administered Sodium D-Thyroxine As A Teratogen In New Zealand White Rabbits, Gary A. Thibodeau Jan 1971

Evaluation Of Orally Administered Sodium D-Thyroxine As A Teratogen In New Zealand White Rabbits, Gary A. Thibodeau

Electronic Theses and Dissertations

Sodium D-thyroxine was evaluated for possible embryotoxic and/or teratogenic effects following oral administration in New Zealand White rabbits. All animals utilized were alert, active and apparently disease-free virgin does weighing three and one-half to four kilograms. Rabbits were individually housed in stainless steel batteries and maintained on a commercially available palletized diet and mineral supplement. Feed and water were provided ad libitum in animal quarters air conditioned to minimize environmental temperature fluctuations. Following a 14-day post-delivery observation period does were bred to New Zealand White bucks and randomly allocated to one of two experimental groups or the control group each …

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An Ecological Study Of Coleoptera Succession In Bovine Manure With Emphasis On Natural Enemies Of The Face Fly (Musca Autumnalis De Geer) In Eastcentral South Dakota, Howard Kessler Jan 1971

An Ecological Study Of Coleoptera Succession In Bovine Manure With Emphasis On Natural Enemies Of The Face Fly (Musca Autumnalis De Geer) In Eastcentral South Dakota, Howard Kessler

Electronic Theses and Dissertations

The frequency and succession patterns of coleopterous species in cattle dung were determined for two localities in eastcentral South Dakota during 1969 and 1970. Thirty-nine species of beetles were screened as potential predators of the face fly, Musca autumnalis De Geer, a pest of cattle and horses; and 1 Coleoptera, 1 Hymenoptera and 1 nematode were screened as parasites of the same host. Succession studies of insects inhabiting bovine manure revealed that four families of Coleoptera were recovered from the manure and, in descending order of abundance, were Hydrophilidae, Staphylinidae, Scarabaeidae, and Histeridae. The hydrophilids were first to invade freshly …

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Effects Of Various Factors On The Rachitogenic Activity Of Isolated Soy Protein, Donald James Arshem Jan 1971

Effects Of Various Factors On The Rachitogenic Activity Of Isolated Soy Protein, Donald James Arshem

Electronic Theses and Dissertations

The nature of the rachitogenic activity of isolated soy protein was investigated in fifteen studies. A RP-100-glucose purified diet was fed to day-old turkey poults housed in stainless steel batteries. Feed and water were provided ad libitum. Corn, oat hulls, solvent-extracted soybean meal, full-fat extruded soybeans, C-1 protein, casein and texturized forms of soy protein were added to the basal diet at various levels. All feedstuffs were added at two particle sizes: natural form of the feedstuff (>250 u); and ground in a ball mill (<250 >u). The effects of autoclaving for 60 minutes at 120°C were also investigated. …

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Effects Of Various Levels Of Dietary Selenium And Arsenic On Chickens, Richard L. Arnold Jan 1971

Effects Of Various Levels Of Dietary Selenium And Arsenic On Chickens, Richard L. Arnold

Electronic Theses and Dissertations

Various levels of selenium and arsenic additions were made to several types of chicken diets to study their effects on growth and reproduction criteria. Three experiments were conducted. The first study involved day-old chicks and terminated at 64 weeks of age. These yearling hens were then used for the second experiments which terminated when the hens were 104 weeks old. The third study was initiated with 20 week old pullets and terminated when they were 52 weeks old. Feeding purified diets resulted in slower chick growth and lower mature body weights of hens. Selenium additions of 2.0 ppm resulted in …

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Field Population And Flight Activity Of Three Hippodamia Species In Eastern South Dakota, Gene Allen Olson Jan 1971

Field Population And Flight Activity Of Three Hippodamia Species In Eastern South Dakota, Gene Allen Olson

Electronic Theses and Dissertations

Twenty-four coccinellid species, excluding the genus Scymnus, were collected in eastern South Dakota during the 1969-70 growing seasons. Hippodamia convergens Guerin-Meneville, H. tredecimpunctata L., and H. parenthesis (Say), were the most abundant species found in alfalfa and small grains. Reproduction of H. convergens and H. tredecimpunctata occurred in alfalfa, oats, spring and winter wheat, and corn. Field observations indicated that the reproductive cycle required approximately 2½ weeks. The pea aphid, Macrosiphum pisi (Harris), the English grain aphid, M. avenae (Fabricius), and the corn leaf aphid, Rhopalosiphum maidis (Fitch), appeared to be suitable food for these 3 Hippodamia species; the brown …

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The Influence Of Various Stress Conditions On Cholinesterase Levels Of Cattle Treated With An Organophosphorus Insecticide, Mitchell J. Wrich Jan 1971

The Influence Of Various Stress Conditions On Cholinesterase Levels Of Cattle Treated With An Organophosphorus Insecticide, Mitchell J. Wrich

Electronic Theses and Dissertations

Six-to 8-months-old Hereford heifers categorized as grubby or grub-free calves were used for this research. Forty calves were purchased in 1968 and also in 1969. The grubby calves were obtained from Highmore, South Dakota, an area where calves have a history of heavy grub infestations of both Hypoderma bovis (L.) and Hypoderma lineatum (de Villers). The grub-free calves were purchased in Fargo, North Dakota. Calves raised in this area seldom are infested with cattle grubs. Specified groups of calves were subjected to 30 minutes of continuous exercise or the withholding of feed and water for 24 hours prior to treatment …

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