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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.
141

Gene expression changes in heifers treated multiple times for bovine respiratory disease

Johnson, Jaymelynn Kay. January 2009 (has links) (PDF)
Thesis (M.S.)--Oklahoma State University, 2009. / Vita. Includes bibliographical references.
142

The Effect of Alternative Fertilization and Application Time on Voluntary Intake of Forages

Clark, Jessica 09 January 2016 (has links)
<p> Dairy slurry and poultry litter have increased in popularity as fertilizers in the agriculture industry. However, residual effects of these manures on voluntary intake of forages from subsequent harvests are not well known. The objectives of this two part study were to determine if moisture level of alfalfa silage and the use of dairy slurry as a fertilizer have an effect on intake and digestibility by sheep, and if forage species and the use of poultry litter as a fertilizer have an effect on intake by horses. Eighteen ewes (47.6 &plusmn; 5.34 kg) were used in experiment 1 and were allocated randomly to 1 of 6 treatments arranged in a 2 &times; 3 factorial treatment arrangement. Treatments consisted of high (HM; 46.8%) or low (LM; 39.7%) moisture alfalfa silage at baling after no slurry application (NS), slurry applied to stubble immediately after removal of the previous cutting (S0) or 14 d after the previous cutting (S14). Experiment 2 used 5 mature geldings (480.3 &plusmn; 52.89 kg) in a balanced incomplete block design to evaluate preference for bermudagrass (B) or teff (T) hay that was harvested after no litter application (NL), litter applied immediately after the removal of the previous cutting (L0) or 14 d after the previous cutting (L14). Animals were housed individually: sheep were housed in 1.4 &times; 4.3 m pens and horses were housed in 3.6 &times; 3.6 m indoor stalls with access to 3.6 &times; 7.6 m outdoor runs. All animals were offered mineral and had <i>ad libitum</i> access to water. Intake by sheep did not differ (<i>P</i> &ge; 0.13) across treatments. Dry matter and OM digestibility by sheep tended (<i>P</i> &lt; 0.10) to be greater for LM compared with HM. In horses, intake was greater (P &lt; 0.01) for bermudagrass and NL and L0 treatments compared with teff and L14. Therefore, the use of manure as a fertilizer may not affect voluntary intake in sheep, but application time may affect intake in horses.</p>
143

5 published articles on studies on the Notostraca

Longhurst, A. R. January 1962 (has links)
This thesis consists of a series of reprints of publications in which are reported the results of researches on the systematica of the Notostracan Crustacea. Studies were made on the cytology, the biochemistry end the comparative ecology of the group and were utilised in a systematic study of the Notostrace. This research was initiated after the finding by the candidate of living Notostraca in a rain-pool in southern England, which proved to be the only known locality for the group in the British Isles in recent years, having been found there previously by Professors Hobson and Fox. Success in culturing Triops cancriformis from this pool under laboratory conditions stimulated efforts to obtain cultures of other species, and finally cultures of all four species of Triops and of two species of Lepidurus were maintained at Bedford College. These, together with the collections of preserved material in a number of European, American and Australian museums, formed the basis of the study. The cultures were utilised for investigations of the development of exoskeletal characters during growth, for the investigation of the variability of these characters in a single line of individuals under differing environmental conditions, for cytological studies resulting in some knowledge of the chromosome numbers within the group, and for an investigation of the specificity of blood pigments in different species and in different races of a single species. The study was recorded in five publications, which are bound together to form this thesis; a preliminary report of the discovery that the so-called parthenogenetic forms are in fact hermaphroditic is bound in as E in the thesis. The main paper, B, contains a review of Notostracan literature, the analysis of the validity to systeraatics of the exoskeletal characters used in the past, the chromosome counts, the investigation of biochemical specificity, and the basic systematic revision of the group. The conclusion reached in this paper was that the Hotostraca are composed of a small number of very widely dispersed species, all rather close to each other systematically but characterised by considerable individual variation. The number of species previously described was shown to be much too high. A separate account of the details of the cytology and reproductive qycle which were elucidated incidentally in the investigation of chromosome numbers appears as D and describes in considerably more detail than hitherto the cytology of the gonads during reproduction. An attempt was made in a separate publication. A, to explain the widespread nature of the distribution of llotostracan species and to relate it to the extreme longevity of the group in palaeontological terms, and an explanatory hypothesis is developed, derived from the ecology of the group. Finally, under C, there is an account of the existence of what appears to be a most unusually high proportion of abnormal individuals occurring in populations of Notostraca compared with the proportion in other animal groups, and this again is referred to the palaeontological longevity of the Botostraca. For convenience the constituent papers of the thesis are listed below: A: Evolution in the Notostraca. Evolution.; B: A review of the Notostraca. Bull. Brit. Mus. (N.H.); C: Abnormal variation in the Notostraca. Syst. Zool.; D: Reproduction in the Notostraca. Proc. Zool. Soc. Lond.; E: Reproduction in the Notostraca. Nature, Lond.
144

Comparison of Retaining Replacement Heifers in a Straight-Bred Angus System Versus Purchasing Crossbred Replacement Heifers to Be Bred to a Terminal Sire

Ruble, Grady D. 20 December 2018 (has links)
<p> Two evaluations were conducted to evaluate the biological and economic production efficiency of retaining replacement females in a straight-bred Angus herd (HR) as opposed to purchasing crossbred replacements for a terminal sire production system (PR) where maximum maternal and individual heterosis is achieved. The first study was a comparison of the HR system versus PR system. It was modeled after a 100 hd, straight-bred Angus cowherd that raises their own replacement females. The (NASEM, 2016) model was used to determine the required metabolizable energy (ME)/animal for each stage of production. Stages were broken into segments including weaning &ndash; d 28, d 29 &ndash; breeding, breeding &ndash; mid-gestation. It was determined, that on the same ME resources, an operator can run 117 cows and produce 7,833 more kilograms in the PR system compared to the 100 cows in the HR system. Economically, the PR system produced $10,949 more dollars of net income than the HR system. In the second study, 25 Angus and 29 SimAngus heifers were placed in the South Dakota State University Cow Calf Education and Research Facility Insentec feeding system, where they were evaluated for dry matter intake, average daily gain, gain:feed, metabolizable energy intake, predicted dry matter intake, and residual feed intake based on NRC prediction equations. At the start of the trial there was no difference in initial BW. The first period (d 1 - 98) featured no difference in BW, DMI, G:F, ME intake, predicted DMI or RFI<sub>NRC</sub>. However, Angus heifers exhibited a greater ADG (<i>P</i> &le; 0.02) than SimAngus heifers. During period 2 (d 99 - 167), heifer BW, G:F, and RFI<sub>NRC</sub> were not different between breeds; however, Angus heifers had a greater ADG (<i> P</i> &le; 0.02), DMI (<i>P</i> &lt; 0.01), ME intake (<i> P</i> &lt;0.01) and predicted DMI (<i>P</i> &le; 0.04). Cumulatively (d 1 - 167) Angus heifers had greater ADG (<i>P</i> &lt; 0.01), DMI (<i>P</i> &le; 0.03), G:F (<i>P</i> &le; 0.05), ME intake (<i>P</i> &le; 0.03), and tended to have greater predicted DMI (<i>P</i> &le; 0.06) than SimAngus heifers, but no difference was observed in RFINRC. Contrary to our initial assumptions, these results show that in this herd, Angus heifers have the advantage in performance, feed intake and efficiency over SimAngus heifers. These results warrant further research with a larger sample size and greater genetic diversity, in order to draw compelling conclusions that explain these biological differences. </p><p>
145

Circadian Rhythm of Intraocular Pressure in Minipigs| First Time Mapping of Rhythmicity and Response to Environmental and Pharmaceutical Factors

Christie, Abigail Harper 03 January 2019 (has links)
<p> Existence of a daily circadian rhythm of intraocular pressure (IOP) in pigs has not been previously published, and is a necessary first step to investigate if minipigs could be used as an animal model for glaucoma. Study goals were to (1) investigate the presence of a pattern of rhythmicity to minipig IOP under a regular light/dark cycle, effects of reversing light/dark cycles on (2) immune response and (3) IOP, and if the (4) topical application of Timolol Maleate lowers IOP. </p><p> Eight female Sinclair minipigs were exposed to regular light/dark cycles. Four baseline IOP collections were taken at least 10 days apart. Data collections were 24 hours, with IOP taken from both eyes every two hours using a Reichert Tonopen XL. Light/dark cycles were flipped ten days prior to reversed IOP data collection. Timolol was administered twice a day, for seven days prior to another IOP collection. </p><p> Baseline data were analyzed by repeated measures ANOVA. There was a significant effect of time, F(11,77) = 12.56, <i>p</i> &lt; 0.001. Bonferroni post hoc tests revealed a significant difference between hour 0 and 6, 6 and 10 (the peaks), and between 10 and 14, and 14 and 0 (the troughs). This supports the hypothesis that minipigs have an daily rhythmicity to their IOP. </p><p> Reversed light/dark data were analyzed by mixed measures ANOVA. There was a main effect of time, F(11,143) = 7.503, <i>p</i> &le; 0.001, no main effect of condition (reversed vs baseline), F(1,13) = 1.092, <i> p</i> = 0.315, and an interaction effect (time*reversed vs. baseline), F(11,143) = 5.384, <i>p</i> &lt; 0.001. </p><p> Paired samples t-tests were run on the baseline complete blood cell count (CBC) and the samples taken during the light/dark cycle reversal to investigate if there was an immune response to light/dark cycle reversal. There was a significant effect on several CBC factors; however, none of the factors were out of the &ldquo;normal&rdquo; for female Sinclair Minipigs. </p><p> The final hypothesis was that Timolol Maleate would lower IOP. A mixed ANOVA was run and revealed that there was a main effect of time, F(11,143) = 5.146, <i>p</i> &lt; 0.001, a main effect of condition (baseline vs Timolol), F(1,14) = 6.511, and a significant interaction effect (time*baseline vs Timolol), F(11, 154) = 2.703, <i>p</i> = 0.003. Because the minipigs displays two peaks and two troughs, which has never been seen before, and Timolol had no effect on IOP, further research is needed before pigs can be used as an animal model for glaucoma research.</p><p>
146

Conservation Status of the Illinois Chorus Frog (Pseudacris illinoensis) in Madison County, Illinois

Hebenstreit, Lisa 20 September 2018 (has links)
<p> The Illinois Chorus Frog (<i>Pseudacris illinoensis</i>) is a state-threatened species that has been impacted by development. <i> Pseudacris illinoensis</i> is found in nine counties in Illinois, predominately along the Illinois River, however, there is an isolated population in Madison County. The population once spanned 15 km<sup>2</sup>, into Granite City and South Roxana, but is now is limited to one isolated population near a mitigation site that was purchased in 1996 for the development of Interstate 255. The last population estimate was in 2002 and was estimated to be 245 individuals and the current status is unknown. This study was conducted to help to preserve a future for this population by evaluating population demography, population range, road mortality, and locating breeding habitat. Mobile Road Surveys were conducted in the Spring of 2015, 2016, and 2018. Four ponds were seined in 2016 to check for successful reproduction. Coordinates were taken for all sightings, choruses, and road mortalities. Maps were created using ArcMap to compare range and areas frogs are most likely to cross the road. Minimum Convex Polygon was used to compare historical range versus present range. Population was unable to be estimated during this study due to lack of recaptures. Females had significantly greater body mass but nonsignificant snout-vent lengths when compared to males. Using Kruskal-Wallis, a segmented survey map showed a significant difference of frogs in the road, with the most near the mitigation site. Minimum Convex polygon showed that there has been a 61% reduction of the range in Madison County. Seining confirmed fish in every pond except one site. It is important that this population be monitored continuously because there is development in the immediate area (less than 0.025 miles from the mitigation site). Future studies should include a population estimate and locations of travel corridors using PIT tags and radio telemetry. Breeding habitat and travel corridors are important land acquisitions to consider. </p><p>
147

Evaluation of Craniofacial Superimposition as a Technique for Measuring Mountain Gorilla Facial Soft Tissue Depth and Implications for Hominid Facial Approximation

Richmond, Marli 25 May 2018 (has links)
<p> Paleoanthropological facial approximation (also known as hominid facial reconstruction) refers to the results and investigations undertaken to determine and represent the life appearance of the earliest humans. Integrating skeletal, biomechanical, behavioral and environmental data, each approximation takes us on a journey through time, embodies decades of research and archaeological discovery, and tells the unique story of a species in anatomic detail. Despite its utility in connecting scientific and public audiences, facial approximation remains hindered by two factors: the first, a lack of methodological standardization and testing within the field, and the second a lack of facial thickness data for non-human primates. </p><p> This study presents a novel application of craniofacial superimposition as a noninvasive way to measure facial soft tissue depth in great apes. Three-dimensional skull models and corresponding ante-mortem images of six adult male mountain gorillas (<i>Gorilla beringei beringei</i>) are overlaid in a computer-automated superimposition, and the point-to-point distances between skull surfaces and outer facial envelopes measured. A series of statistical analyses assess variation in measurements due to the type of software and number of images used. Further comparisons are drawn between mountain gorillas, chimpanzees, and humans in facial tissue thickness. Results support craniofacial superimposition as a measurement approach. However further study is needed to determine the technical limits that may occur in practice and improve methods for use in facial approximation and paleoanthropology.</p><p>
148

Experimental Approaches to Understand and Control Salmonella Infection in Poultry

Yang, Yichao 16 December 2017 (has links)
<p> <i>Salmonella</i> is a major foodborne pathogen around the world and chickens are the major reservoir to transmit <i>Salmonella </i> into the human food chain. For decreasing the infection of <i> Salmonella,</i> we developed six attenuated live vaccines based on <i> Salmonella</i> Enteritidis (SE) and Typhimurium (ST) for testing the cross-serovar and cross-serogroup protection from the challenge of <i> Salmonella</i> Heidelberg and <i>Campylobacter jejuni.</i> One of the constructed vaccine strain showed ability to protect against challenge from <i>Salmonella</i> Heidelberg. Even though some preventive approaches are able to decrease <i>Salmonella</i> colonization in the gastrointestinal tract of chickens or other farm animals, <i>Salmonella</i> transmission mechanisms remain unclear. For analyzing <i>Salmonella</i> transmission routes and dynamics, we designed a series of <i>Salmonella</i> isogenic barcode-tagged strains by inserting six random nucleotides into a functionally neutral region on the chromosome of <i>Salmonella</i> Enteritidis. These barcode-tagged strains can be used as a tool for quantitative tracking of <i>Salmonella</i> transmission in the chicken flock by profiling the barcode regions using high-throughput sequencing. The efficiency of this novel approach has been estimated by chicken experiments and can be applied for further studies about <i>Salmonella</i> transmission and population dynamics. Due to the increasing pressure of using antibiotics as the growth promoter in the farm animals, probiotics is a suitable alternative to replace antibiotics by providing beneficial effects, such as promotion of animal health, decreased infection by pathogens, and improval of growth performance in poultry. In this study, 90 probiotic candidate strains were isolated and evaluated for decreasing the gut permeability in Caco-2 cell lines. The result from animal experiments indicated that a combined batch culture of 3 selected strains showed significant efficacy in controlling intestinal colonization of ST in neonatal turkey poults.</p><p>
149

The Relation of Some Physical and Chemical Factors of the Soil to the Productivity and Distribution of Certain Waterfowl Food Plants at the Bear River Migratory Waterfowl Refuge

Jensen, Grant Hortin 01 May 1940 (has links)
Within the last raw years several areas thin the state of Utah have been and are being developed for the conservation of migratory birds. Of utmost importance in this respect is the management of these areas so as to obtain a sufficient supply of rood plants for use by water fowl. Previous work done at the Bear River Migratory Waterfowl Refuge shows that the productivity or aquatic rood plants, chiefly Potamogeton pectinates L. and Ruppis marittima L. varies with different localities and that these differences could not be attributed to chemical conditions of the water, i.e., dissolved oxygen, alkalinity, and hydrogen ion. Inasmuch as little was done on the soils. it was felt that soil characteristics might have some street on the productivity and distribution or the aquatic plants at this locality. Results from such a problem would undoubtedly aid in rut development or these habitats; hence the study seems opportune and might be or value.
150

Nitrogen Excretion of Lactating Dairy Cows Fed an Alfalfa Hay- or Birdsfoot Trefoil Hay-Based High-Forage Diet

Khan, Mohammad Ghelich 01 May 2017 (has links)
Extensive research has been conducted to decrease the environmental impacts of dairy farming by using forages containing condensed tannins (CT). In this study, it was hypothesized that feeding CT-containing birdsfoot trefoil (Lotus corniculatus, BFT) to lactating dairy cows would result in a decrease in N degradation in the rumen, causing a shift in N partitioning into milk and manure outputs, compared with alfalfa hay. Urine N is more volatile and harmful to the environment compared with fecal N. By reducing urine N, overall N utilization efficiency can improve. It was our goal to verify how the changes in N partitioning would affect the overall N utilization efficiency by dairy cows fed BFT hay-based high-forage diet. The results in this report showed that feeding BFT-hay diet reduced protein degradation in the rumen, decreased N excreted to milk and urine, and increased N excretion into feces, resulting in decreased urinary-N:fecal-N ratio due to feeding BFT-hay diet. However, the change in the N excretion routes was not associated with N utilization efficiency, which may have resulted from poor nutritive quality of BFT hay. Although the BFT hay fed in the current study was in a very mature condition and was of poor quality, DM intake and milk yield were similar in both treatments. Therefore, it is implied that BFT hay can replace alfalfa hay in dairy rations, because even poor quality BFT hay compared with alfalfa hay led to similar lactational performance and a beneficial shift in N excretion into environment.

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