The only practical method for artificially breeding ewes with frozen semen is laparoscopic insemination into the lumen of the uterine horn. Like all surgical procedures, however, laparoscopic artificial inseminatiom has limitations. The procedure requires surgical skill and costly equipment. Repeated passage of the laparoscope through the abdominal wall causes adhesions. Depositing frozen/thawed semen at the os cervix results in low conception rates. The inability to pass an insemination pipette through the cervix has prevented artificial insemination in sheep from becoming a standard breeding method as in the cattle industry. This study compared laparoscopic and transcervical methods of insemination in nulliparous ewes and transcervical insemination in multiparous ewes after estradiol cypionate treatment. Forty nulliparous commercial-cross Rambouillet ewes were treated with pessaries containing fluorogesterone acetate to synchronize estrus. After 14 days, pessaries were removed and ewes were injected IM with 400 IU of pregnant mare serum gonadotropin (PMSG). Ewes were randomly divided into laparoscopic and transcervical treatment groups, 14 and 26 respectively. Ewes were inseminated with thawed semen (75x106 motile spermatozoa). Pregnancy rate with laparoscopic insemination was 85% (confirmed at 55 days with real-time ultrasound) .. With the transcervical method, the speculum could only be inserted into the vagina of five ewes and the insemination pipette could only be passed through the cervix in two ewes. The combined pregnancy rate for deep cervical and transcervical insemination was 40% at 55 days. Forty multiparous commercial-cross Rambouillet ewes were synchronized as previously described. Ewes were randomly separated into a control and estradiol cypionate treatment group of 20 animals each. Within each group 10 ewes were inseminated with frozen/thawed Suffolk semen and 1 Owith Rambouillet semen. Ten ewes within each sire genotype were treated with 1 mg IM of estradiol cypionate 16 hours prior to insemination. Treated ewes were inseminated into the uterine body 90% of the time and non-treated ewes 95%. There was no significant difference in cervical passage between these groups. Pregnancy rates for transcervical artificial insemination in the Suffolk genotype were 0.05% and 40% in the Rambouillet (pregnancy confirmed at 55 days by real-time ultrasound). Lambing rates for the Suffolk and Rambouillet groups were zero and 0.05%, respectively.

Subnivean prey appeared to be the primary reason for subnivean access point use by martens. A logistic regression was used to create a predictive model for differential access point use. Prey biomass in grams and percent ground cover of coarse woody debris (CWD) were used as variables in the model. Goodness of fit of the multivariate model was 0.216; biomass was significant al p = 0.0003, CWD was significant at p = 0.0718. Mean values for prey biomass at used and unused access points were 174.2 g and 81 g, respectively, while mean values of CWD were 24.7% and 18.5%, respectively. Both CWD and prey can be used to predict access point use by martens. CWD provides access to the subnivean zone. Martens appear lo key in on access points with higher levels of prey. Red squirrel middens were found at 33% of used and 16% of unused access points (p = 0.015, n = 90). There was no significant difference in prey biomass or CWD based upon the presence or absence of a squirrel midden. Prey biomass was significantly related to access point use (p = 0.0022) and the relationship was strengthened when squirrels were included in the biomass estimates (p = 0.0001). It is likely that red squirrel middens were used as access points by martens because of the opportunity to prey on red squirrels as a prey item. Seed boluses were used to estimate the relative prey abundance at subnivean access points. Use of seed boluses in winter was correlated with prey abundance values obtained by snap trapping after the snow melt (J2 = 0.0134, ¢2 = 0.435). A program for direct entry of raw telemetry data in a Geographic Information System (GIS) data base was developed. With this method telemetry data can be interpreted directly al a number of scales to determine habitat patterns using area rather than point data.

There are numerous proteins that have potential uses in commercial and scientific applications that are not utilized to their full potential. this is partly because it is not economically feasible to isolate some of these proteins from their natural sources or to produce them using bacterial fermentation methods. The purpose of this research was to target recombinant protein expression to the mammary glands of genetically engineered or transgenic animals. Foreign protein expression has been achieved in the mammary glands of rabbits, sheep, cows, and swine. By using a strong mammary gland promoter and signal peptide fused to the protein, it was hypothesized at the beginning of the study that the two proteins of this study would be secreted into the milk. To test this approach for protein production, expression vectors for two different plant proteins were made. The proteins targeted for expression were thaumatin and brazzein, proteins that have sweetener or flavor altering properties. The regulatory portion of the expression vector used exons and introns from the milk β-casein gene. Four and a half kilobases of the 5' region of the bovine β-casein gene was isolated, which contained the promoter sequence and other regulatory sequences for gene expression in mammary tissue. A size of 2.2 kilobases of the 3' region of the β-casein gene contained further regulatory sequences as well as a polyadenylation signal. The gene sequence for the protein was modified by using codons commonly used for casein and was generated using synthetic oligonucleotides. Additionally, the signal peptide from the alpha S-1 casein gene was used to transport the protein into the mammary milk vesicle. The DNA expression vectors were subsequently injected into murine and caprine embryos for the production of transgenic animals. Transgenic mice and a goat were identified that contained the thaumatin transgene. Preliminary analysis of mouse milk by capillary gel electrophloresis indicated the expression of thaumatin protein. This protein expression system is intended to utilize large dairy animals as bioreactors for efficient, non-toxic protein production with a view to being applied to different proteins as the technology advances.

Zika virus (ZIKV) is a sexually transmitted viral infection most frequently transmitted by mosquitoes. The source of infectious virions in the male reproductive tract has yet to be elucidated. The goals of the studies included developing and characterizing two mouse models for reproductive transmission studies and demonstration of sexual transmission of virus via artificial insemination. The mouse strains used in the study lacked receptors to interferon molecules, key signaling proteins of the host immune response. Inflammation severity was assessed during acute disease, 5-11 days after infection using a novel histopathology grading system. ZIKV proteins and genome were initially detected in epididymal epithelial cells in males. Inflammation was first observed in the epididymis and progressed to the testicle in both AG129 and Ifnar-/- males. Infection of Ifnar-/- mice may better recapitulate Zika virus pathology in humans due to milder histopathologic lesions, the presence of histologically normal sperm in epididymal tubules, and an ability to survive the acute phase of disease. In further studies, male Ifnar-/- mice were challenged subcutaneously with ZIKV. Artificial insemination fluid derived from experimentally infected males showed positive sexual transmission at 7 days post infection (DPI) but not 35 or 70 DPI. These studies show passage of virus from epididymal flush and seminal plasma to females via insemination during acute ZIKV disease in males and provides a model for sexual transmission of ZIKV.

For many years sportsmen have speculated that hunting limits pheasant populations. With the abolition of the Pheasant Game Farm program in Utah in 1953, this popular concept gained much impetus with the result that, because of public disfavor to a longer season, a 3 to 5 day season on pheasants is the maximum that bas been called in northern Utah and this only in areas classed as "better" pheasant habitat. In contrast to the short seasons in Utah, pheasant seasons in southern Idaho have been from 8½ to 15½ days long for the past 10 years, and will be even longer in 1956 (table 1). Since the topography and land-use patterns of southeast Idaho and northeast Utah are similar, the question has been asked by Cache County sportsmen, "how can Idaho maintain a 15½ day season in Franklin County, while just across the line here in Cache County, we have only a 3 to 5 day season?" Thus the purpose of this study was to investigate some of the factors affecting pheasant populations of northeast Utah and south-east Idaho under differing season lengths. Objectives of the study were to determine (1) the response of contiguous pheasant populations to long (15½ day) and short (5 day) seasons, (2) the hunting pressure under the 2 season lengths, (3) harvest of the pheasant crop under the 2 season lengths, and (4) reaction of hunters, farmers, and land-owners to long and short seasons.

A major challenge in ecology is to understand intraspecific variation in life histories. Variation in resource availability can lead to differences in reproductive allocation and life histories. Grasshoppers are a good organism for the study of variation in life histories, since they exhibit life history plasticity in response to biotic and environmental factors. An optimality model for grasshoppers was developed that predicts optimal total allocation to reproduction and optimal effort-per-offspring as functions of resource availability and mortality. Relative allocation to reproduction is predicted to increase with resource availability, while relative allocation to survival declines. A resource-based trade-off between egg size and number does not exist, as optimal egg size is predicted to be independent of resource intake. I examined if changes in reproductive allocation and survival of Melanoplus sanguinipes (Fabricus) under a range of resource availabilities fit the predictions of the model. The patterns of reproductive allocation and survival in the field were in qualitative agreement with the predictions. I examined the importance of density, resources, and parasitism on the life history patterns of grasshoppers. I conducted an experiment to examine if differences in reproductive allocation of M. sanguinipes are primarily explained by exploitative competition. Per capita resource availability explained a significant amount of the variation in reproduction , as expected with exploitative competition. M. sanguinpes grasshoppers appeared to trade off resource allocation to reproduction for that of allocation to survival, because per capita resource availability did not affect survival. Careful examinations of changes in life history characteristics in response to parasitism are lacking, despite the fact that parasites often influence resource availability for the host. I investigated the effects of a grasshopper ectoparasitic mite on grasshopper reproduction and survival. Mites had small effects on grasshopper survival. As predicted, both species had reduced initial and total reproduction, and completed development of a lower percentage of ovarioles initiated when parasitized. These experiments act to expand our knowledge of life history theory and further our understanding of grasshopper life history variation and population fluctuations.

As bison are considered to be ecologically extinct, and negative interactions between bison and cattle are perceived to limit bison restoration and cattle production, I designed a series of studies to test for potential competition between bison (Bison bison) and cattle (Bos taurus) for forage on the Henry Mountains in southern Utah. These studies provide insight into key information gaps previously identified by the Utah Division of Wildlife Resources (UDWR), Bureau of Land Management, and the local grazing association. The results indicate that bison and cattle are not strong competitors for forage on the Henry Mountains. Jackrabbits (Lepus californicus) emerged as the strongest competitive threat to cattle, consuming more than twice the amount of forage consumed by bison. Further, bison habitat preferences did not match with cattle habitat needs as reported by a survey of the local ranching community. This suggests that negative impacts on cattle due to bison have been overstated. Still, any potential negative impacts of bison will be felt by a small group of local individuals. This prompted me to design a new management scheme, which has the potential to increase the number of bison on the Henry Mountains while also compensating local ranchers for reducing the number of cattle they graze in the area. This system should be mutually beneficial for the local ranching community and the UDWR, and easily implemented by taking advantage of the currently exiting conservation license program.

The purpose of this study was to explore the response v of coyotes (Canis latrans) to certain olfactory and visual stimuli. It was assumed that the findings would be of value in refining techniques used in sampling and controlling coyotes. The specific objectives were to determine (1) if coyotes were more likely to approach and remain in the vicinity of a familiar than unfamiliar scent, (2) if the response to olfactory and visual stimuli differed, (3) if positively reinforcing an approach to the stimuli differentially altered the response to visual and olfactory stimuli, and (4) if the response differed with sex and social rank. The results failed to reject each of the null hypotheses implicit in the four objectives. Two factors that may have contributed to these findings were that subjects were too accustomed to "novelty" and there was a lack of behavioral control during the tests. On the basis of the results of this study, it is suggested that coyotes are so sensitive to their surroundings and so accommodating in their behavior that behavioral test results may simply reflect their responses to specific captive and test conditions.

In recent years, Zika virus (ZIKV) has garnered worldwide attention due to its epidemic spread throughout the Americas and due to the newly recognized link between ZIKV infection and neurological diseases, including microcephaly and Guillain-Barré syndrome. ZIKV is a mosquito-borne member of the genus Flavivirus, which includes the other prominent human pathogens Japanese encephalitis virus, West Nile virus, dengue virus, and yellow fever virus. Many questions about the biology of ZIKV and how it causes disease remain unanswered. Furthermore, there currently are no vaccines or licensed antiviral drugs available to treat ZIKV infection. The goal of this study was to create new tools to aid in ZIKV research and in the creation of new therapies for ZIKV infection. To accomplish this, we created two recombinant ZIKVs–one expressing a green fluorescent protein reporter gene and the other expressing a luciferase reporter gene. These additional genes will allow us to easily visualize infected cells and to precisely track levels of viral replication over time, thereby facilitating new experimental approaches and providing a means to gain insights about ZIKV. We believe that these two new versions of ZIKV will prove to be useful tools in the urgent task of better understanding how ZIKV causes disease and its links to other complications, as well as in the process of developing and testing new treatments to combat ZIKV infection.

Origin and purpose of research Dichloro-diphenyl-trichloroethane or DDT as it is more commonly known, was first used extensively by the armed forces in the Pacific Area during World War II. This insecticide is not only a very toxic contact and stomach poison, but also is quite residual on most types of surfaces. Because of these qualities, it was selected to control the malaria mosquito and thus aided in the conquest of many disease-ridden islands of the Pacific. When DDT became available to the general public after the war, it was found not only to be effective against mosquitoes but also many other types of insects. Among these insects are the alfalfa weevil (Hypera postica hon.) and lygus bugs (Lygus elisus Van D., Lygus hesperus Knight) that had previously impaired the production of alfalfa in Utah and other areas. Although treatment of alfalfa fields is usually confined to alfalfa for seed production, DDT-dusted alfalfa straw and DDT dusted alfalfa hay are fed to farm livestock. In ruminant animals, microorganisms play an important role in the synthesis of protein from nitrogenous non-protein compounds and also aid in the break-down of many complex plant materials so that they may be more fully utilized by these animals. The purpose of this study was to determine the effect of DDT upon the role played by the microflora and fauna of the rumen in the synthesis, digestion and utilization of certain nutrients by dairy calves. Scope Digestion and balance studies were conducted with Holstein bull calves fed different levels of DDT and protein equivalent in the ration. The experiment was designed so that each calf would receive one level of DDT throughout the experiment, and would receive a low protein basal diet plus three additional levels of protein equivalent. These additional protein levels were made up by adding a nitrogenous non-protein compound, urea, to the basal diet to give an increased level of protein equivalent in the diet. The nitrogen, calcium, and phosphorus balance and the digestibility of dry matter, protein, and ether extract were determined.