Life Sciences Commons^™

Pastoral Development Strategies In The Sahel And East Africa: Can The Mistakes Be Corrected?, Ahmed Musa Haji Ahmed

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

There is much controversy on the definition given to those people who raise livestock on the natural vegetation. Differences in the degree of their dependence on livestock and livestock products for food, as well as differences in the patterns of their movements, create the controversy. "Pure-pastoralists", "nomadic pastoralists", "semi - pastoralists", "semi-nomadic", "transhumant", and "semisedentary" are but some of the many terms used in the literature to describe them (see, for example, Johnson, 1969; Jacobs, 1965; McGee, 1986; Horowitz, 1981). To avoid much of the confusion created by the use of these terms, we use the definition of pastoralists as …

Acquisition Of Forgaging Skills By Lambs Eating Grass Or Shrub, Enrique R. Flores

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the acquisition of foraging skills by lambs eating shrub or grass in three experiments. The general approach was to isolate those skills involved in prehending forage from those related to the acceptance of novel foods. Treatment lambs received 15 times more exposure to grass or shrub than did control lambs. Lambs were tested in 2.5 x 2.5 meter monocultures of shrub or grass 5 min/d, on two separate occasions. Height, bulk density and spatial arrangement of plant material were controlled during testing.

In Experiment 1, I studied the acquisition of foraging skills by lambs on monocultures of shrubs. …

Analyses Of Somaclonal Variation In Hexaploid Wheat (Triticum Aestivum L.), Zahra Noori Hashim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Somaclonal variation, to provide germplasm for crop improvement, must be screened, selected and characterized. Immature wheat, Triticum aestivum L., (PCYT-10) embryos (10-12 days old) were cultured on Hurashige and Skoog (MS) medium containing 0.5 mg L^-1 6-furfurylaminopurine (kinetin) and 2, 3, or 4 mg L^-1 of 1-methoxy-3,6-dichlorobenzoic acid (2,4-D). Dicamba, at 2 and 3 mg L^-1 and 0.2 mg L^-1 2,4-D, produced 12.7%, 30.3%, and 28.2% of the somaclones, respectively. No plantlets were produced from other treatments. Variants were characterized by cytology, biochemistry and morphology. Somaclones showed significant differences in length and width of flag leaf, …

Early Career Development Processes Of Women And Men Resource Managers In The Usda Forest Service, Joseph Anthony Mincolla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to understand the similarities and differences in the early careers of women and men resource managers in Regions 4 and 6 of the U.S. Forest Service (FS). Since the early family socialization of boys and girls has been shown to differ, it was hypothesized that differences would also be found in the early career goals of men and women and in their ability to fit into an organization like the Forest Service, experience personal satisfaction, and become contributing, productive members.

Although more similarities than differences were observed, women had slightly different definitions of two …

A Simple Model To Predict Optimal Harvest Time Of Alfalfa Using Near Infrared Reflectance Spectroscopy, Environmental, Morphological, And Growth Parameters, Jody A. Gale

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Knowledge of relationships between nutrient levels, yield, maturity, and environmental influences on alfalfa (Medicago sativa L.) are necessary to estimate when to harvest alfalfa to maximize quality and yield. Objectives were to document the change in nutrient content, yield, and growth stage of alfalfa grown in Utah as it matures and to develop a simple model to predict optimal harvest date. The study involved three locations in major alfalfa producing regions in Utah. Samples were collected from three commonly grown alfalfa varieties between 26 April and 26 September in 1987. Maximum and minimum levels of crude protein (CP) observed were …

Using Adaptive Conjoint Analysis And Market Simulations To Determine The Effect And Usefulness Of Nutrition Label Information In Consumer Purchase Decisions, Constance J. Geiger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrition labeling research suggests consumers want nutrition information on the label; however, many do not comprehend it. The purpose of Phase I was to determine the effect of: 1. two levels of nutrition label formats; 2. three levels of nutrition information load on consumers' preference for product choice using adaptive conjoint analysis. A computer interactive interview was conducted on 252 consumers in Crossroads Mall, Salt Lake City, Utah. label alternatives were printed on soup cans to realistically portray the information. The conjoint analysis compared the attributes, nutrition information format, and nutrition information load in addition to brand and price and …

A New Approach To Forest Site Quality Modeling, David L. Verbyla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiple regression and discriminant analysis procedures are commonly used to develop forest site quality models. 'When they contain many independent variables relative to sample size, these models may be subject to predicton bias. Fit statistics such as R² in regression and classification tables in discriminant analysis show the apparent model accuracy but this may be a biased estimate of the model's actual accuracy. Sample splitting methods such as cross-validation and the bootstrap can be used to get an unbiased actual accuracy estimate.

A discriminant procedure called classification tree analysis uses cross-validation to build the classifier with the greatest estimated …

Inter-Seasonal Range Relationships Of Spanish Goats And Mule Deer In A Utah Oakbrush Community, Robert Alexander Riggs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three experiments were conducted to assess the potential for using Spanish goats to manage Gambel oakbrush winter range, dominated by Gambel oak (Quercus gambelii), for mule deer (Odocoileus hemionus). Summer-time food selection of goats, effects on plant community composition, and consequent effects on mule deer nutrition and foraging behavior were examined.

An apparent preference for juvenile oak browse, and low use of oak twigs was observed. Selection for juvenile browse may have been facilitated by the retarded phenology of oak as compared to that of associated flora. This differential was maintained by repeated browsing. Animal performance, …

Characterization Of Esterases And Glutathione S-Transferases In A Solitary Bee, Megachile Rotundata (Fab.): Variability, Developmental Multiplicity, Substrate Specificity, And Inhibition, Donald R. Frohlich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The esterases and glutathione S-transferases of a solitary bee, Megachile rotundata (Fab.) (Hymenoptera: Megachilidae), the alfalfa leafcutting bee, were characterized by electrophoresis, substrate specificity, and inhibition studies. Comparisons were made between ages, sexes, and life stages for several classes of substrates and their isomers: aromatic, aliphatic, and thio-esters. Two esterases were found to be allozymes and variable between individuals and sexes. Adults typically possess an esterase that hydrolyzes fluorescent substrates, an organophosphate insensitive esterase, and a series of type 'B' esterases that are very sensitive to organophosphate inhibition. Electrophoretic patterns are different between adults and immatures and are probably …

Studies On Encephalomyocarditis Virus-Induced Diabetes In Mice, John Henry Huffman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The D-variant of encephalomyocarditis (EMC-D) virus was given to SJL/J mice by the artificial, intraperitoneal (ip) route of infection, or by the natural routes of infection per os (po) or intranasal (i.n.), in comparable concentrations. The po route of infection was found to be ineffective. Mice given virus by either the ip or i.n. routes of infection became diabetic. Mice were more resistant to the infectious and diabetogenic properties of the virus when given by the i.n. than when given by the ip route. Glycosuria in mice given virus i.n. usually lagged one day behind that in mice given virus …

Effect Of Feeding A Viable Yeast Culture On Ruminal Fermentation Characteristics, Milk Production Response And Apparent Nutrient Digestibility In Holstein Cattle, Mohamed H. Shokair

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Four barren Holstein cows fitted with ruminal fistulas were assigned to each of two dietary treatments in a replicated 2 x 2 Latin square design. Treatments consisted of a basal ration and a basal ration plus 10g/d of a viable yeast culture (Saccharomyces cerevisiae). Cows were fed treatments for a 21-day adaption followed by a 7-day collection period. Total ruminal bacteria, cellulolytic bacteria and protozoa were unaffected by treatment. Feeding the viable yeast culture significantly increased ruminal acetic acid and acetic/propionic ratio. Molar percentage of propionic, isobutyric, isovaleric and valeric acids and rumen ammonia-N levels were significantly reduced …

Effect Of Bacterial Inoculant On Alfalfa Haylage: Ensiling Characteristics And Milk Production Response When Fed To Dairy Cows In Early Lactation, Barb Kent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Third-cutting alfalfa hay harvested at bud stage in each of 2 yrs, treated with a live bacterial inoculant, packed in polyethylene-bonded bags and allowed to ensile. In both years, treated haylage had a lower pH, and a period effect was found for pH and mold count, regardless of treatment. In year 1, there was a period effect found for acid detergent fiber. In year 2, mean lactic-acid-producing bacteria numbers (log 10) were significantly higher for treated haylage (9.69 and 10.36) for control and treated haylage, respectively). Regardless of treatment, lactic-acid-producing bacteria numbers and water soluble carbohydrates significantly declined through time. …

The Immunological And Neurochemical Toxicity Of Benzene And Its Interaction With Toluene In Mice, Gin-Chang Hsieh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Benzene and toluene are known groundwater contaminants . Male CD-I mice were continuously exposed to 0, 31, 166, and 790 mg/ L benzene and 0, 17, 80, and 405 mg/L toluene, respectively, in drinking water for four weeks. Benzene caused a reduction of leukocytes, lymphocytes and erythrocytes, and resulted in a macrocytic anemia. Lymphocyte response to both B- and T-cell mitogens, mixed lymphocyte response to alloantigens, and the ability of cytotoxic lymphocytes to lyse tumor cells were enhanced at the lowest dose of benzene and depressed in the higher dosage animals. Benzene at doses of 166 and 790 mg/L decreased …

Nutrient And Water Interrelationships Between Crested Wheatgrass And Two Shrub Species, Paul B. Baker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When crested wheatgrass (Agropyron desertorum) grows in mixture with sagebrush (Artemisia tridentata), its production declines. Its production increases when grown in mixture with fourwing saltbush (Atriplex canescens), according to previous reports. This study investigated soil water extraction and potassium (K) nutrition of the two shrubs to identify possible causes of the differential responses of crested wheatgrass.

Crested wheatgrass had reduced, rather than increased, nitrogen (N) and K yield in mixture with fourwing saltbush. No differences in N and phosphorous (P) concentrations were observed between sagebrush and fourwing saltbush, but fourwing saltbush had a much …

The Feasibility Of River Otter Reintroduction In Northern Utah, Joel P. Bich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to document river otter (Lutra canadensis) distribution and reintroduction potential in northern Utah. Distribution was studied using data from 3 sources: 1) otter sighting records from Utah Division of Wildlife Resources; 2) surveys of Utah furbearer trappers and natural resources personnel; and 3) searches of streams for otter sign. Potential for river otter habitat/reintroduction was evaluated by assessing food, cover, and reintroduction attributes. Streams were ranked using an evaluation system based on data from the otter literature.

Forty-six positive otter sightings were made in Utah by trappers, natural resources personnel, and the …

Factors Affecting Recovery From Defoliation During Drought In Two Aridland Tussock Grasses, Carlos Alberto Busso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The importance of several factors in limiting recovery from defoliation was investigated in field-grown plants of Agropyron desertorum and Agropyron spicatum exposed to drought , natural or irrigated conditions. Leaf extension rate, components of leaf area production, number of metabolically active axillary buds and carbohydrate availability were examined on the same plants immediately after defoliation and/or in the following spring from 1984 until 1986.

The diurnal course of leaf growth did not relate to turgor pressure in the expanded portion of leaf laminae. Rather growth was apparently associated with air temperature. Leaf extension rate was lower under drought than under …

Effect Of Fertilization On Woody Plant Chemistry: The Role In Diet Selection By Goats, Amanuel Gobena

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lack of forage quantity and quality limit livestock production during the dry season in northeast Brazil. Coppice produced following cutting of tree species in this area has the potential to increase forage quantity and quality during the dry season, because trees that coppice retain green foliage throughout most of the dry season. However, the palatability of coppice is often low.

From a theoretical standpoint, woody plants with inherently slow growth rate should be less palatable to herbivores than plants with inherently fast growth rates, because plants that grow slowly allocate more carbon to compounds such as tannins and resins that …

Maternal Iron Parameters And Diet: Influence On Infant Iron Parameters And Development, Janet Bradshaw Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine and evaluate the dietary intake of pregnant women living in this geographical area, evaluate how their diets related to their iron status, how their nutrient intakes compared with other studies, and how their iron status and diet affected infant iron status and development, as assessed by the Bayley Scale of Infant Development.

The study involved 32 pregnant women who were between 8 to 14 weeks gestation and 20 to 35 years of age. They were followed through pregnancy and their infants were followed until three months of age.

Three-day dietary records, a …

Patterns Of Singing By House Wrens With Respect To The Breeding Cycle, Michael H. Tove

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I recorded the songs and studied the reproductive behavior of a population of marked House Wrens (Troglodytes aedon) to identify patterns of singing and correlate them with behavioral contexts and stages of the breeding cycle. I found that House Wren singing could be organized into three hierarchical regimes: routine patterns of daily singing, context-specific patterns of singing and long-term fluctuations in singing rate throughout the breeding cycle. During routine daily singing, predictable structural changes occurred. Songs were clustered in discrete groups called bouts. The songs within a bout were more similar in structure than songs from different bouts. …

Winter Ecological Energetics Of Blue Grouse, Peter Jeffrey Pekins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study investigated relationships between blue grouse (Dendragapus obscurus) winter habitat and blue grouse adaptive strategies and overwinter survival. Blue grouse metabolism, physical characteristics of use-trees and roost sites , microclimatic parameters at roost sites, daily winter energy costs, and specific energy-saving behaviors were studied. Blue grouse have a relatively low standard metabolic rate (SMR; 0.835 ml 0₂ · g^-1 · hr^-1) and lower critical temperature in comparison to other northern tetraonids . Metabolic rate did not significantly increase from -5 to -20 C. Ambient temperature (T_a) and the square root of …

Comparison Of Post-Weaning Performance And Carcass Traits Of Columbia And Cormo Crossbred Lambs, Carl Kim Chapman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thirty-seven Columbia and Cormo Crossbred July-weaned weather lambs were utilized in this study. A feeding trial was conducted to evaluate feed efficiency, average daily gain, feed cost per pound of gain, wool growth per day and per pound of grain, and average wool fiber diameter and distribution of fiber population of the wool. Lambs were raised to a uniform market weight of between 115 and 125 pounds and slaughtered to evaluate carcass weight, backfat thickness, loin eye area, internal body fat, leg circumference, dressing percentage, untrimmed wholesale cuts, trimmed retail cuts, and yield and quality grades. Suffok x Cormo/Rambouillet lambs …

Characterization Of Chemical And Radiation-Induced Dna Damage In The Mdbk Cell Culture System, Jeffrey R. Hincks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mechanism common to many carcinogens and mutagens is the interaction with cellular DNA. Alkaline elution is a sensitive and commonly used technique to detect cellular DNA damage in the form of DNA single-strand breaks (SSB), DNA-protein cross-links (DPC), and DNA interstrand cross-links (ISC). In the present study, gravity-flow alkaline elution was developed and validated to rapidly detect DNA damage in the MDBK cell culture system by genotoxic agents.

The system was first validated by detecting a dose dependent induction of DNA SSB in cells exposed to 25-1500 rad of X-ray. The assay reliably detected the DNA damage of seven …

Fire Frequency And The Vegetal Mosaic Of The Utah State University Experimental Forest, Linda L. Wadleigh-Anhold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A fire history study conducted for the Utah State University (USU) Experimental Forest using three distinct periods of fire frequency, historic (1700-1855), settlement (1856-1909), and suppression (1910-present), showed a decreased mean fire interval (MFI) during the settlement period and a greatly increased MFI during the suppression era. The difference was attributed to the influx of ignition sources during the settlement of the nearby Cache Valley, located 40 kilometers to the west. The interaction of settlers with the resource during logging and livestock grazing activities encouraged the high MFI and created the vegetal mosaic now observed on the study area.

The …

Alfalfa Weevil, Hypera Postica (Gyllenhal), (Coleoptera: Curculionidae) Response To Environmental Factors In Alfalfa Fields In Northern Utah, Larry Edward Jech

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Economic damage to forage alfalfa by the alfalfa weevil occurs frequently enough in northern Utah to warrant applications of an insecticide in some years but not all. Currently a five to ten day period is available to recognize injurious populations then make applications.

Sticky boards, pitfall traps, Berlese funnels sweep samples, stem bouquets, climatic variation and marking techniques were evaluated for alfalfa weevil population predictions. The prevailing climate was the most important factor controlling early adult activities. Early adult feeding and sexual development was the key to forecasting later larval populations. Regional surveys were not adequate for local control recommendations. …

The Bioavailability Of Iron From Meat, Spinach, Soy Protein Isolate, Meat:Spinach And Meat:Spi Mixtures Fed To Anemic And Healthy Rats, Dejia Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two Experiments were conducted to investigate the effect of iron status and iron source on iron bioavailability using the rat model. Beef was proportionally mixed with spinach (Experiment I) or soy protein isolate (Experiment II) to test if meat enhances the absorption of iron from spinach or SPI. Five diets with the iron from meat:spinach (or SPI) ratios of 100:0, 75:25, 50:50, 25:75 and 0:100 were prepared and fed to rats. FeS04 was used as a reference. Two trials of rats were used in Experiment I. In trial I, half of the rats were made severely iron deficient (Hb 6.3 …

Measurement Of Proteins In Milk And Dairy Products, Marie K. Walsh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to develop a short, easy procedure to measure five major proteins in milk and to detect concentrations of added protein to dairy products. Combinations of casein or whey protein with nonfat-dry milk were made with concentration ratios from 0:10 to 10:0. Similar mixtures of defatted goat milk with defatted cow milk were prepared. Samples were hydrolyzed in 6 N HCl at 145°C for 4 h and analyzed for amino acid composition. Multiple regression equations were derived to estimate the relative content of whey protein or casein added to nonfat-dry milk and goat milk added …

Evaluation Of Frogurt: A New Product Prepared By Fermentation Of Ice Cream Mix, Morteza Mashayekh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ice cream mix was fermented with yogurt cultures of Streptococcus thermophilus and Lactobacillus bulgaricus to four different pH's then frozen in a batch ice cream freezer. A consumer panel of 120 people tasted samples of strawberry flavored product with pH's of 4.4, 4.7, 5.1, and 5.4 and commercial frozen yogurt as a standard. Results from the panel were used to predict a preferred pH of 4.9. Another panel of 181 people compared product at pH 4.9 with 10, 15 and 20% strawberry flavoring. There was not a statistically significant difference among levels of flavoring.

Starter culture populations and lactase activity …

Luteinizing Hormone An Progesterone Response To Gnrh Administration At Insemination In Repeat-Breeder Holstein Cows, Robert Joseph Callan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several studies suggest that the administration of GnRH near the time of insemination improves pregnancy rates in cattle. It has also been reported that there is greater improvement in repeat-breeder animals than at first service. The mechanism for this observation has not been established. Twenty-eight lactating Holstein cows that returned to estrus after one or more inseminations from the USU Caine Dairy were used in the study. Animals were randomly divided into two treatment groups, intramuscular administration of 100 ug GnRH or saline control at the time of insemination. Blood samples were collected at 1, 1.5, 2, 2.5, 3 and …

The Effects Of Gonadotropin Releasing Hormone And Milk Production On Pregnancy Rates In Repeat Breeder Dairy Cows, Laura Maureen Mitchell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One hundred sixteen third- and fourth-service lactating dairy cows from five cooperating herds were used to compare the pregnancy rate of cows given Gonadotropin Releasing Hormone five minutes following insemination with pregnancy rate of control cows. In addition, milk production level, age at service and days in milk at time of service were used to compare pregnancy rates. Milk production level was expressed as relative value (percent of herd mature equivalent production). There were no differences between treated and untreated control cows in pregnancy rate. In addition, there were no differences between service number (3 or 4), relative value group, …

Gambel Oak For Spanish Goats: A Digestion-Balance Evaluation Of Nutrient Availability, Brian L. Dick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fresh-harvested Gambel oak (Quercus gambelii) browse was mixed with chopped alfalfa hay to formulate six diets, varying in oak content at two phenological stages. Diets included juvenile oak (65,80,95%), mature oak (40,80%), and an alfalfa control. Diets were evaluated for goats using a series of total-collection digestion balance trials. Dry matter intake was highest for animals on mature oak diets, and lowest on diets containing a high percentage of juvenile oak, possibly due to differences in diet dry matter content. Apparent digestibility of dry matter and cell wall components was lowest for mature oak diets, and highest for …