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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

USING THE INDICATOR AMINO ACID OXIDATION TECHNIQUE TO STUDY THREONINE REQUIREMENTS IN HORSES FED DIFFERENT FEED COMPOSITIONS

Mok, ChanHee 01 January 2015 (has links)
Threonine has been reported to be the second limiting amino acid in typical equine diets, but its actual requirement has not been determined in horses. The indicator amino acid oxidation (IAAO) method has been successfully used for evaluating amino acid metabolism and requirements in animals and humans. The objective of this research was to use the IAAO method to estimate threonine requirements in mature horses fed two different feed compositions. In the first study, 6 Thoroughbred mares (4 – 16 years old) received each of 6 levels of threonine intake in a high concentrate diet, in a randomly determined order. The experimental diets consisted of concentrate at 0.95% of body weight (BW), and chopped timothy hay at 0.95% of BW, and met or exceeded NRC recommendations for all nutrients. Threonine intakes for the 6 treatments were 45, 56, 67, 79, 90 and 102 mg/kg BW/d and were generated by mixing the two experimental concentrates, containing 2.9 and 14.8 g threonine/kg diet, in different ratios. In the second study, horses received each of 6 levels of threonine intake, 41, 51, 61, 70, 80, and 89 mg/kg BW/d, in a high forage diet, in a randomly determined order. The experimental diet was concentrate at 0.4% of BW, and chopped timothy hay at 1.6% of BW. Study periods for each study were 7-d long and on d 6, blood samples were collected before and 90 min after feeding to measure amino acid concentrations using HPLC. On d 7, horses underwent IAAO procedures, which included a two hour primed, constant intravenous infusion of [13C]sodium bicarbonate to measure total CO2 production and a four hour primed, constant oral administration of [1-13C]phenylalanine to estimate phenylalanine oxidation to CO2. Blood and breath samples were collected to measure blood [13C]phenylalanine, using GC-MS analysis, and breath 13CO2 enrichment, using an infrared isotope analyzer. Experimental data were analyzed using a one-way ANOVA, including orthogonal linear and quadratic contrasts, in the mixed procedures of SAS version 9.3, with treatment as the fixed effect and horse nested in treatment as the random effect. Statistical significance was declared at P0.05). Increasing threonine intake levels in a high forage diet did not affect plasma phenylalanine oxidation by the ANOVA test (P>0.05) but resulted in a linear decrease in phenylalanine oxidation (P=0.04) without a breakpoint by the orthogonal linear contrast. Threonine requirements are still unknown in mature horses fed either high concentrate or high forage diet. The present studies were the first attempt to evaluate threonine requirements in horses by the indicator amino acid oxidation method.
172

Effects of pre-partum and post-partum bolus injections of trace minerals on performance of beef cows and calves grazing native range

Mundell, Lauren Rae January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / K C Olson / Our objective was to evaluate the effects of pre- and post-partum bolus injections of a trace mineral solution on beef cow reproductive performance, body weight (BW) change, and body condition score (BCS) change and on performance of suckling calves. Mature beef cows (n = 460; initial BW = 497 ± 89 kg, initial BCS = 5.4 ± 0.74) were stratified by BCS, parity, and predicted calving date and assigned randomly to 1 of 2 treatments: 1) subcutaneous trace mineral (TM) injection containing 15 mg/mL Cu, 5 mg/mL Se, 10 mg/mL Mn, and 60 mg/mL Zn or 2) subcutaneous injection of physiological saline (SA). Injections were administered to cows (1 mL / 90 kg BW) 105 days before the first projected calving date and again 30 days before fixed-time AI. Calves received the same treatment as their dams and were injected (1 mL / 45 kg BW) at birth and again at 71 ± 21 days of age. Cows grazed native pastures for the duration of the study; trace mineral supplements and white salt were available to all cattle ad libitum before and during the study. Ovulation was synchronized using a 5-d CO-Synch + CIDR protocol and cows were inseminated 60 to 64 hours after CIDR removal. Cows were exposed to fertile bulls for natural-service breeding 10 days after AI for 35 to 50 days. Conception to AI and final pregnancy rate were assessed 36 days after AI with ultrasound and 120 days after AI via rectal palpation. Change in BW and BCS from initiation of the study to calving and from AI to weaning did not differ (P ≥ 0.15) between TM and SA cows. Conversely, TM cows had greater (P = 0.04) BCS increase than SA cows between calving and AI. Calf BW at birth, ADG, and age-adjusted weaning BW did not differ (P ≥ 0.36) between treatments. Proportion of cows with estrus cycles 17 and 8 days before ovulation synchronization was similar (P ≥ 0.51) between treatments. Conception to AI was greater (P = 0.05) for cows receiving TM (60.2%) than for cows receiving SA (51.2%); however, overall pregnancy did not differ (P = 0.24) between treatments and averaged 92%. Under the conditions of our study, pre- and post-partum TM injections improved conception to fixed-time AI by beef cows.
173

Assessment of adrenal activity and reproductive cycles during captive management in the fishing cat (Prionailurus viverrinus)

Fazio, Jilian M. 22 July 2016 (has links)
<p> Fishing cats (<i>Prionailurus viverrinus</i>) are a small felid found primarily throughout Southeast Asia. Wild populations have been rapidly dwindling due to degradation and loss of habitat along with retribution killings. Captive populations have been established throughout the world to help ensure this species persists. In North America, Species Survival Programs (SSP) are committees formed within the Association of Zoos and Aquariums (AZA) to help manage captive populations of threatened and endangered species. The SSPs are made up of a group of species-specific experts dedicated to sustaining a healthy captive population that can serve to educate the public and potentially replenish dwindling wild populations if needed in the future. The SSPs make breeding recommendations for each species based on genetics, age and keeper intuition. Often because of a genetically valuable animal&rsquo;s age, there is only one chance to create a successful breeding pair. It was hypothesized that individual fishing cats would differ in their adrenocorticol response during transfer between institutions and during breeding introductions. The prediction was that glucocorticoid levels would have a direct correlation with the manner in which the individuals are managed and overall breeding success. </p><p> The study ultimately had four objectives: 1. Examine the current management and breeding behaviors of captive fishing cats. 2. Validate a glucocorticoid assay for longitudinal monitoring of exogenous stressors on adrenocortical activity in males and females. 3. Determine relationship between adrenal activity and gonadal function in females. 4. Characterize temperament within the population and correlate with behavioral traits, breeding success and adrenal activity. </p><p> The study ran from 2010-2013 monitoring 27 (13 male; 14 female) fishing cats at 17 institutions which included 15 unique breeding pairs and 20 transfers (13 males, 7 females), which occurred primarily in the fall (62%). Validation of a single antibody cortisol enyzme immunoassay (R4866 supplied by C.J. Munro, University of California, Davis, CA, USA) was performed using standard assay validation. In addition, an adrenocorticotropin challenge revealed peak glucocorticoids metabolites (GCM) occur approximately 21 hours after adrenal stimulation. Longitudinal monitoring revealed significant elevations in GCM concentrations during institutional transfers lasting 54 &plusmn; 16 days indicating most individuals take at least three months to settle into a new facility after translocation. Most initial physical breeding introductions during this study (83%) occurred within that timeframe. Mate compatibility seems rigid with pairs copulating between 39-289 days after quarantine release, or not at all, indicating a one year trial period for pairs is sufficient to determine potential breeding success. Increases 4-10x in baseline GCM concentrations were observed during periods of chronic illness (i.e. hepatitis) and therefore could be used to help diagnose acute health concerns in this species. </p><p> Reproductive activity occurred throughout the year and was not impacted by institutional transfers. Natural pregnancies (n = 5) all occurred March-July and 67% of females exhibited one or more periods of anestrus lasting 66-181 days beginning most often April-August (67%). Highest mean progestogen and estrogen concentrations occurred between December and August. Differences in peak estrogens, occurring approximately 8 days (range 0-30) into non-pregnant luteal phases (NPLP) and 40 days (range 32-49 days) into a pregnancy may help distinguish the two. A high percentage of females (58%) exhibited spontaneous ovulation during the study period with no clear ovulation mechanism. Ovulation may be influenced by age or induced by external stimuli, other than intromission during copulation - such as semiochemicals detected in shared enclosure spaces or tactile contact through mesh enclosures. The species high reliance on aquatic habitats also may lend itself to resource dependant stimulation of the hypothalamus pituitary gonadal axis, such as annual rainfall or access to large pools of water, which bears further investigation. </p><p> Recommendations include transfers in the late spring or early summer of males allowing at least three months post quarantine release for physical introductions, to allow the tranferred individual time to return to baseline GCM concentrations before experiencing another stressful event (breeding introductions). Institutions with breeding pairs can improve breeding success via reducing fishing cat stress levels with positive animal keeper interaction through training and providing indoor off-exhibit refuge areas. It is also suggested that videotaping breeding introductions and providing at least 1-2 nest boxes for females may all contribute to greater captive breeding success in the fishing cat. </p><p> The information gained by this study provides an outline for fishing cat SSP managers on how this species is managed in captivity. It also provides a solid foundation of longitudinal monitoring of adrenal activity and provides recommendations for the future sustainability of the <i>ex situ</i> population. (Abstract shortened by ProQuest.)</p>
174

A Powerful Approach or the Power of Horses| Is Equine-Assisted Psychotherapy an Effective Technique or the Natural Effect of Horses?

Iwachiw, Jessica S. 03 May 2017 (has links)
<p> The lives of humans and animals have been intertwined through time immemorial, and in many instances the relationship between humans and animals has been thought to be good for human well-being. As such, it is not surprising that treatments for a wide range of ailments, from physical to psychological, have developed that capitalize upon the relationship between humans and animals. While animal-assisted interventions have become popular in practice, the research-base of evidence to demonstrate the effectiveness of these approaches is limited. Research is needed to clarify the effectiveness of animal-assisted approaches using well-controlled and randomized samples, and to help shed light on the mechanisms of effectiveness for these techniques. While a variety of animals are used for psychotherapeutic intervention, horses are of particular interest because of the qualities that distinguish them from traditional household companion animals. The size, power, and sensitive nature of horses are thought by many to serve as a foundation for personal growth and psychological healing for humans. The current study evaluated the impact of equine-assisted psychotherapy (EAP) versus traditional contact with horses on the depressive symptoms of five at-risk adolescents. Results suggest that structured contact with horses in either a horsemanship or EAP context may be both enjoyable, engaging, and beneficial for at-risk youth within the areas of depressive symptoms, social skills, and coping skills. Additional skills, such as persistence and problem-solving, may be uniquely impacted by EAP.</p>
175

Testing camera trap density estimates from the spatial capture model and calibrated capture rate indices against kangaroo rat (Dipodomys spp.) live trapping data

Walker, Timothy A. 01 November 2016 (has links)
<p>Camera trapping studies often focus on estimating population density, which is critical for managing wild populations. Density estimators typically require unique markers such as stripe patterns to identify individuals but most animals do not have such markings. The spatial capture model (SC model; Chandler & Royle, 2013) estimates density without individual identification but lacks sufficient field testing. Here, both the SC model and calibrated capture rate indices were compared against ten sessions of live trapping data on kangaroo rats (Dipodomys spp). These camera and live trapping data were combined in a joint-likelihood model to further compare the two methods. From these comparisons, the factors governing the SC model?s success were scrutinized. Additionally, a method for estimating missed captures was developed and tested here. Regressions comparing live trapping density to the SC model density and capture rate were significant only for the capture rate comparison. Missed image rate had a significant relationship with ambient nighttime temperatures but only marginally improved the capture rate index calibration. Results showed the SC model was highly sensitive to deviations from its movement model, producing potentially misleading results. The model may be effective only when movement assumptions hold. Several factors such as camera coverage area, microhabitat, and burrow locations could be incorporated into the SC model density estimation process to improve precision and inference.
176

Aposematic Variation and the Evolution of Warning Coloration in Mammals

Fay, Caitlin 13 April 2017 (has links)
<p> Aposematic prey animals use conspicuous, high contrast color patterns to warn potential predators that they possess a defense mechanism. Avian predators show an innate phobia of bold, contrasting color patterns, and can readily learn to avoid a prey item displaying bold warning coloration. Signal uniformity is important to promote predator learning and memory retention; however, there is documented variation in the aposematic pattern of many species, including the striped skunk (<i>Mephitis mephitis</i>). Most of the literature on aposematism refers to studies using avian predators and insect prey &ndash; we know relatively little about how mammalian predators learn about and interact with aposematic prey, despite the recognized influence of predation on the evolution of aposematism in mammals. This study examined the behavior of coyote (<i>Canis latrans</i>) subjects during interactions with baited black-and-white models that were able to spray a dilute skunk oil solution. Coyotes are the most common mammalian predator of striped skunks. To test their ability to generalize, after being sprayed coyotes were introduced to a variant model design based on natural documented variation in striped skunk pelage. The results demonstrate that coyotes show innate wariness of a black-and-white striped model, and most can effectively learn to avoid the model after being sprayed. Variants with proportionately more white incited more avoidance behaviors than darker patterns, although they did not allow for greater signaling power than the diagnostic black-and-white striped pattern. </p>
177

Survey of Swine Disease, Management and Biosecurity Practices of Hawai'i Swine Farms

Castle, Brittany Amber 08 March 2019 (has links)
<p> Although swine diseases and parasites cause significant losses to producers in Hawai&lsquo;i, limited information is available on changing disease patterns and related farm practices. The objectives of this study were to identify practices used on Hawai&lsquo;i swine farms and to determine if there is a relationship between those practices and the absence or presence of a disease. A management and biosecurity practices survey was administered to farmers (n = 27). Survey questions were analyzed by region, sow population, and disease presence. Most common practices included cooking food waste (94% of farmers feeding food waste), feral pig exclusion (74%), and administering an anthelmintic (63%). Challenges faced by farmers include biosecurity concerns of on-farm sales, limited access to veterinary specialists, and excluding vermin from the production area. In addition, serological samples (n = 414) from swine farms (n = 57 out of 200 farms) were tested and found positive for antibodies against Porcine Circovirus Type 2b (PCV ELISA; 98% positive), Senecavirus (SVA IFA; 58%), Porcine Epidemic Diarrhea (PED IFA; 33%) and Porcine Reproductive and Respiratory Syndrome (PRRS ELISA; 16%). Fecal flotation detected coccidia oocysts (63%) on every island; Oesophagostomum dentatum (26%), Ascaris suum (18%), Strongyloides (11%), Metastrongylus spp. (8%), and Trichuris suis (8%) ova were on a subset of islands. Analysis indicates that disease prevalence is regionally distributed. Kaua&lsquo;i, which is protected by a quarantine order, has remained negative for PED, and Moloka&lsquo;i, which sees less interisland traffic, is negative for PRRS, PED, and SVA. Geographical patterns in disease distribution assist biosecurity and management practice recommendations, the design of vaccination protocols, and the judicious use of antibiotics.</p><p>
178

Skeletal Development in Oviparous and Viviparous Populations of Saiphos equalis.

Baker, Melia 07 May 2011 (has links)
This study examines ossification at different embryonic stages to develop a pattern of ossification and to look at differences between oviparous and viviparous populations of the same species.
179

A Study of the Seasonal Incidence of the Arthropod & Helminth Parasites of the Prairie Vole, Microtus Ochrogaster, & the Wood Mouse, Peromyscus Leucopus, in an Area of Warren County, Kentucky

Buckner, Richard 01 June 1972 (has links)
One-hundred and fifty Microtus ochrogaster and one-hundred and fifty-five Peromyscus leucopus were examined for arthropod and helminth parasites during a study from November, 1970 through November, 1971. The mean monthly burdens, per host, of each species of parasite and observations on the seasonal incidence of each species are reported. Nineteen species of arthropod parasites were found; these include eight species of mites, two of chiggers, one of ticks, two of lice, five of fleas, and one of hots. Most of these species exhibited very little host specificity, although there was a definite host preference. Heavier ectoparasite burdens were found on M. ochrogaster than P. leucopus. The majority of the ectoparasites of M. ochrogaster were mites, with the predominate species being Dermacarus hypudaei and Listrophorus leukorti. Chiggers comprised the largest portion of the ectoparasite burden of P. leucopus. The species found were Euschoengastia peromysci and Neotrombicula caviola. Three species of cestodes and three species of nematodes were found in M. ochrogaster. The most common helminth parasites were the cestode species Paranoplocephala variabilis and Aprostatandrya macrocephala. Four species of nematodes were found in P. leucopus. The most common species was Syphacia peromysci. Immature Thelazia sp. were found under the eyelids of six P. leucobus. This nematode has not been previously reported for the genus Peromyscus.
180

The Wavelength Dependency of Ultraviolet Induction of Simian Virus 40 from a Transformed Line of Baby Hamster Kidney Cells

Bichenbrenner, Timothy 01 July 1976 (has links)
For our investigation, an established line (E line) of baby hamster kidney cells which was transformed by the incorporation of Simian Virus 40 into the cellular genom was used. The induction of this virion by irradiating these cells with ultraviolet light was studied. The purpose of this thesis was to determine the wavelength dependency (at four selected ultraviolet mercury emission lines) of the induction of the SV40 genome from these cells. The viral titres of induction were measured by the agar overlay plaque assay method and by the fluorescent antibody microassay technique. At the four wavelengths tested 265 nm and 280 nm were approximately equal in their ability to induce the virus from the cells. Light at 240 nm was less effective than either of these two wavelengths in inducing virus production. The 297 nm wavelength proved to be the least effective of all four wavelengtns tested.

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