Life Sciences Commons^™

A Descriptive Study Of Range Livestock Operations In The Somali Central Rangelands, Abdinasir M. Abdulle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Information on livestock operations, particularly what kind of livestock operations are practiced in the Somali central rangelands, and how these operations differ for different herders in different vegetation types and farming systems, could serve as a major tool in making management decisions. This study provides a detailed description of range livestock operations in the Somali Central Rangelands. It also answers some important management questions.

Range livestock operations were inventoried through personal interviews with the owners and herders. Data are supplemented by previous nation-wide and regional survey statistics. Herd productivity data which include herd structures, age, age-related sales, slaughters, gifts, and …

The Importance Of Cover For Juvenile Rainbow Trout In Lentic Systems: Field Observations And An Experimental Study On Predation, Roger Allen Tabor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Juvenile rainbow trout Oncorhynchus mykiss stocked into mid-elevation reservoirs in Utah are vulnerable to predation from piscivorous fish and birds. I determined how effectively juvenile trout used cover to avoid these predators by (1) direct observations (snorkel transects) of habitat selection in two reservoirs and (2) measurements of survival and growth rates in a pond experiment where adult brown trout Salmo trutta were predators. Observations of juvenile trout were conducted within five weeks of stocking in 1988 and 1989. During the day, juvenile trout were abundant in complex inshore habitats and avoided simple habitats such as sand and gravel. Measurements …

The Effect Of Seasonal Cattle Grazing On California Bighorn Sheep Habitat Use, Melanie J. Steinkamp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of seasonal cattle grazing on a newly reintroduced population of California bighorn sheep (Ovis canadensis californiana) in Big Cottonwood Canyon, Idaho, was studied. The hypothesis that bighorn sheep avoid cattle was tested. The issue of avoidance between bighorn sheep and livestock is arguable. Some studies have found that bighorn sheep avoid cattle while others have found no response of bighorn sheep to cattle.

Evidence was found to document the avoidance of cattle by bighorn sheep. The size of the bighorn's home range and core area decreased with the movement of cattle into areas of high bighorn …

A Comparison Of Three Estrous Detection Management Schemes For Dairy Heifers, Ann Lagerstedt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heifers should represent the greatest genetic potential within a dairy herd. To maximize this potential, heifers must be inseminated to proven sires, a practice requiring management changes on many dairies. Holstein heifers (n=115) were allotted to one of three groups to compare alternatives to daily estrous detection that may facilitate the management of a program of artificial insemination for heifers. Group 1 heifers (Controls) received no treatment but were observed twice daily for signs of estrus. Group 2 heifers (2X-PGF) were synchronized with two injections of prostaglandin F2 alpha given 11 days apart and observed for estrus. Group 3 heifers …

Effects Of Ketoconazole On Uterine Weight And On Unbound Serum Estradiol Relative To Vaginal Cornification In Rats, Leonard L. Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ketoconazole is a broad-spectrum antifungal with oral activity and is documented to block steroid biosynthesis in fungi and mammals.

Estradiol-primed ovariectomized rats lose the estradiol-induced, cornified layer of the vaginal epithelium as a result of ketoconazole treatment. This effect is not explained by current knowledge of ketoconazole's mechanism of action.

Ketoconazole's effect on estradiol's binding to either receptors in target tissues (target-cell receptors) or serum-estradiol-carrying proteins in the aforementioned rats was investigated.

The uterus is responsive to estradiol treatment, which causes an increase in uterine size and weight. This tissue is a sensitive means of studying the effects of ketoconazole …

The Effects Of Methionyl Bovine Somatotropin Administration On Luteinizing Hormone In Dairy Cattle, Joseph Charles Dalton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sixteen lactating regularly cycling dairy cows (14 primiparous, 2 multiparous) were used to determine the effects of somatotropin administration on basal, peak, and pulse luteinizing hormone concentrations during the breeding period. In addition, the effects of somatotropin administration on the pituitary response to a gonadotropinreleasing hormone challenge was studied. The experimental group received daily somatotropin treatments (25mg) for 24 days. The control group received a daily placebo. All animals were treated with three injections of prostaglandin F2-alpha (25 mgjtreatment) for estrus synchronization. Somatotropin and placebo treatments began with the second prostaglandin injection. Sixty hours following the final prostaglandin injection, all …

Endocrine Interrelationships During Early Postpartum In St. Croix Sheep, Richard Michael Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relationships of estradiol-17-beta, progesterone, and LH in the early postpartum St. Croix ewe were monitored during the breeding season in 1988. A second group of non-postpartum, ovariectomized St. Croix ewes were used to determine non-ovarian levels of progesterone for comparison. Results of this study indicate that:

1. The short duration rise in progesterone exhibited by some ewes is indicative of an ovulation.
2. Ewes that do exhibit a short luteal phase prior to the first "normal" luteal phase have a longer period from parturition to the first "normal" luteal phase.
3. Serum levels of LH increase beginning 3 days postpartum.
4. There is …

Effects Of Cannulation, Bst Administration And Protein Degradability On Rumen And Duodenal Characteristics And Milk Production Response In Holstein Dairy Cows, Margaret D. Winsryg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bovine somatotropin (bST) is a protein synthesized at the base of the brain and released by the pituitary gland into the circulatory system. BST is transported by the circulatory system and absorbed only by cells of target organs that possess cell surface receptors for the protein (11, 41). Its effect is initiated via a protein receptor initiation and cyclic AMP cascade. This effect on the cell continues well past the degradation of the bST molecule. BST is likely transported into the cell, where it is degraded. Its constituent blocks, amino acids, are used to synthesize new proteins or converted to …

Recreation Specialization And Preferences Of Utah Anglers, Bruce P. Andersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purposes of this study were to gain a better understanding of anglers and angler preferences and to examine differences between subgroups of anglers based on level of specialization. Understanding these similarities and differences between user groups will provide valuable input for more effective fisheries management.

A randomized mail survey was sent to resident, adult fishing-license holders in Utah. A 68% response rate yielded 1216 usable returns for data analysis. An analysis of three recreation specialization dimensions (participation, equipment and investment, and lifestyle) and further analysis of participation and investment variables were used to develop a typology of Utah anglers. …

The Response Of Coyotes To Novel And Familiar Visual And Olfactory Stimuli, Yiting Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 …

Chromosome Abnormalities As A Possible Cause Of Reduced Fertility In Dairy Heifers, Stanley L. Henderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chromosome evaluations were made on leukocyte blood samples from 169 phenotypically normal nulliparous Holstein heifers. These were from three different reproduction groups collected in sets of threes from 10 different herds in the western United States. Group 1, the control group, consisted of heifers diagnosed pregnant after one or two breedings; Group 2 consisted of heifers diagnosed pregnant after three or four breedings; and Group 3 consisted of heifers diagnosed open after four or more breedings. Metaphase chromosome spreads used in these analyses were obtained through 72-hour leukocyte cultures from heparinized whole blood. Processed cells were dropped onto a slide, …

The Effects Of Disease, Prey Fluctuation, And Clear-Cutting On American Marten In Newfoundland, Canada, Richard J. Fredrickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Individual variation in survival and behavior of American marten (Martes americana) was studied in relation to disease, prey fluctuation, and clear-cutting from 10 January 1986 through 20 August 1987 in Newfoundland, Canada. Thirty-seven of forty marten captured on the study area were telemetered and monitored for part or all of the study.

Marten mortality was concentrated in two intervals, fall 1986 and late winter 1987. Mortality during fall 1986 was attributable to encephalitis, while marten deaths during late winter 1987 resulted from predation and starvation attributable to the prey decline. Nonsuppurative encephalitis was first detected 7 October 1986; …