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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.
81

Are gopher tortosies (Gopherus polyphemus Daudin) comapatible with cows?

Hentges, Thomas William 02 July 2014 (has links)
Many Gopher Tortoise populations are in steep decline throughout Florida, and various measures have been attempted to curb the trend. One such measure is to relocate tortoises to protected recipient sites on private lands. The majority of private lands in Florida are used for cattle, however, production and the effect of cattle production on tortoises is not known. Here, I tested six parameters of tortoise behavior by monitoring 1403 gopher tortoises released at the Barthle Brothers Ranch, Pasco County Florida, between August 2009 and December 2012. The parameters tested were (1) burrow density, (2) burrow spacing, (3) burrow relocation, (4) body condition, (5) individual growth rate, and (6) recruitment (addition of young to the population). I used telemetry techniques to observe movement and burrow placement as it related to cattle activity and burrow impacts, and collected morphological data to determine changes in body condition and growth. I used burrow surveys and analyzed movement patterns to interpret the propensity for tortoises to place burrows where cattle may or may not congregate. Lastly, I investigated recruitment of juveniles into the population and followed the mortality of resident and relocated tortoises in all treatment plots. I found that burrow density, distance moved when relocating to new burrows, and avoidance of cattle were not distinguishably different within or between the plots. Burrow relocation, however, was more frequent outside the exclosures. The change in body condition did not differ between males and female or resident and relocated individuals. Females within the exclosure did not grow at a rate different than those outside the exclosure although translocated females grew faster than resident females. Densities of non-adult burrows inside the exclosures were not different then densities outside the exclosure. Eleven percent of tortoises relocated to the ranch died during the project. Although we have no evidence that cattle and tortoise cannot successfully coexist, a number of circumstances prevented rigorous testing of our hypotheses, predominately the failure of the silt fence used to enclose the treatment plots. Using a trespass-proof perimeter fence would allow a better assessment of the actual interaction between the cattle and tortoises and may shed new light on the lack of recruitment and the decline of juvenile tortoises relocated to the ranch. Without recruitment of individuals back into a population, or the persistent of reproducing adults within the population, any efforts to curb the downward trend in gopher tortoise numbers by relocating tortoises to actively grazed pasture is futile.
82

'The Bobby Calf' - non linear and non classical narrative structures in the cinema of unease

Scrivin, Nicholas January 2008 (has links)
This document outlines the research, development and production of a creative work and accompanying exegesis in partial fulfilment of the requirements for the Master of Communication Studies (MCS) programme. It includes the first draft of a feature film screenplay and an exegesis that explores the research conducted, the theoretical context of the work, and analyses the screenwriting process undertaken. The Bobby Calf (2008) is the first draft of a feature film screenplay that uses a non-classical and non-linear narrative structure to tell the story of its main characters and advance the plot. A psychological drama set in rural New Zealand, The Bobby Calf (2008) was originally inspired by the Janet Frame short story The Reservoir (1963), a story based on a group of youngsters who venture forth to discover the forbidden reservoir; a place their parents had forbid them from going. Set in the outskirts of a small farming settlement, the story is a dark and gothic depiction of rural life and the harshness of reality faced by those brought up in a lifestyle they did not choose. The story focuses on the journey of ADAM (21); both as a young boy in 1988 (called JOHNNY) and as a young adult in 1997, and his mother CATH; a woman whose dreams and aspirations for her son and indeed her own life are slowly slipping away. The story centres on Adam as he grows more uncomfortable with how his life has ended up, and his discovery that the life he has been destined to fulfil is not the one he has chosen. Accompanying the screenplay is an exegesis that explores the research conducted previously on the history of non-classical/non-linear narrative structures and the rationale behind the success and limitations of this now-popular form of storytelling. These types of narrative structures are not a new phenomenon, and as many authors have attested, the basis of this form of storytelling is rooted in the history of screenwriting and film making, and borrows many techniques from theatre and literature.
83

Net Returns to Alternative Weaning Dates in Beef Cow-Calf Operations

Savage, Gregory Edward 01 May 2010 (has links)
There is sparse research literature in agricultural economics regarding early weaning as a potential alternative production/marketing strategy. The objective of this research is to estimate and analyze the impacts on net returns of alternative weaning dates for Tennessee cow-calf operations including alternative post-weaning treatments for calves. The Decision Evaluator for the Cattle Industry (DECI) simulation program was used for this study to produce outputs such as calf numbers, gender, and weights, other output including cow weights and body condition score, both at calving and at weaning, and pregnancy percentages. Forty-two simulations were run for average and summer drought weather, weaning at an average age of 135, 165, 195, 225, 255, and 285 days and selling at weaning or after a 60 or 90-day drylot backgrounding period. Prices for steers, heifers, and culled cows from 1995-2008 were taken from market reports. Costs were derived from University of Tennessee Extension Beef and Forage Budgets and USDA-NASS. The outputs from DECI were combined with prices to result in total revenues. Subtracting the costs of feed, interest, veterinary and medical, and marketing resulted in return to land, labor, management, and risk to the enterprise. The results of this study revealed that under average weather conditions in East Tennessee, marketing at weaning in November yielded the highest net return. Weaning in August and backgrounding for 60 days yielded the lowest net return with the base 90-cow herd. Under summer drought conditions, marketing at weaning in August resulted in the highest net return. Weaning in November and marketing after a 90-day backgrounding period yielded the lowest net return. Under the conditions used in this study, the only time early weaning makes economic sense is when herd size is increased for June or July weaning or under drought conditions when August (195 days) weaning and sale is optimal. Several limitations of this study imply that additional research is required on this topic before definite conclusions can be drawn.
84

Carcass characteristics, fatty acids, stearoyl-coa desaturase gene expression and sensory evaluation of calf-fed and yearling-fed angus steers

Brooks, Matthew Alan 15 May 2009 (has links)
There is a growing interest in documenting the effect of diet on the ability to convert saturated fatty acids (SFA) to monounsaturated fatty acids (MUFA) by modulating expression of the SCD gene. We propose that if cattle were raised to a constant body weight, their MUFA:SFA ratio will be the same regardless of being calf-fed (CF) or yearling-fed (YF). Twenty-four Angus cattle were acquired for this study. Cattle were slaughtered at weaning at 8 mo of age (SFCF, n=4), eight steers were assigned to the CF group and slaughtered at 12 mo of age (MFCF, n=4) and 16 mo of age (LFCF, n=4). Twelve cattle were assigned to the YF group and slaughtered at 12 mo of age (SFYF, n=4) 16 mo of age (MFYF, n=4) and market weight of 525 kg (LFYF, n=4). Cattle were then statistically analyzed based on time on high energy diet. Fatty acids from digesta, plasma, liver, L. dorsi, and s.c. and i.m. adipose tissue were all analyzed by FAME. In s.c. 18:1 and 16:1 were greatest in LFCF (41.27% and 5.58%, respectively, P = 0.05), and 18:0 and 16:0 did not differ between groups (P > 0.10). MUFA:SFA ratios of s.c. tended to be higher in LFCF animals (1.26) vs. LFYF (1.06, P = 0.10). However, there was no difference seen when comparing CF to YF animals (P = 0.26). MUFA:SFA ratio was higher in i.m. (P = 0.03) and also increased with age (P < .01). A trained sensory panel saw no significant differences between palatability of flavor characteristics of cooked steaks from LFCF, MFYF, or LFYF (P > 0.05). We showed increased SCD gene expression in the LFYF (248.41 to 1528.69 SCD/GAPDH, P = 0.01). Expression was higher in YF (P = 0.04), but their initial deposits of SFA, combined with the lack of SCD expression while on pastures, prevented the MUFA:SFA ratio from increasing at a rate fast enough to change the final ratios in the animal.
85

Carcass characteristics, fatty acids, stearoyl-coa desaturase gene expression and sensory evaluation of calf-fed and yearling-fed angus steers

Brooks, Matthew Alan 15 May 2009 (has links)
There is a growing interest in documenting the effect of diet on the ability to convert saturated fatty acids (SFA) to monounsaturated fatty acids (MUFA) by modulating expression of the SCD gene. We propose that if cattle were raised to a constant body weight, their MUFA:SFA ratio will be the same regardless of being calf-fed (CF) or yearling-fed (YF). Twenty-four Angus cattle were acquired for this study. Cattle were slaughtered at weaning at 8 mo of age (SFCF, n=4), eight steers were assigned to the CF group and slaughtered at 12 mo of age (MFCF, n=4) and 16 mo of age (LFCF, n=4). Twelve cattle were assigned to the YF group and slaughtered at 12 mo of age (SFYF, n=4) 16 mo of age (MFYF, n=4) and market weight of 525 kg (LFYF, n=4). Cattle were then statistically analyzed based on time on high energy diet. Fatty acids from digesta, plasma, liver, L. dorsi, and s.c. and i.m. adipose tissue were all analyzed by FAME. In s.c. 18:1 and 16:1 were greatest in LFCF (41.27% and 5.58%, respectively, P = 0.05), and 18:0 and 16:0 did not differ between groups (P > 0.10). MUFA:SFA ratios of s.c. tended to be higher in LFCF animals (1.26) vs. LFYF (1.06, P = 0.10). However, there was no difference seen when comparing CF to YF animals (P = 0.26). MUFA:SFA ratio was higher in i.m. (P = 0.03) and also increased with age (P < .01). A trained sensory panel saw no significant differences between palatability of flavor characteristics of cooked steaks from LFCF, MFYF, or LFYF (P > 0.05). We showed increased SCD gene expression in the LFYF (248.41 to 1528.69 SCD/GAPDH, P = 0.01). Expression was higher in YF (P = 0.04), but their initial deposits of SFA, combined with the lack of SCD expression while on pastures, prevented the MUFA:SFA ratio from increasing at a rate fast enough to change the final ratios in the animal.
86

The Regulation of Salmonella Typhi Vi Capsular Antigen Expression in Intestinal Model Epithelia and the Bovine Ligated-Ileal Loop Model

Tran, Quynh Tien-Ngoc 2009 August 1900 (has links)
Salmonella enterica serovar Typhi, a major public health concern in developing countries, continues to be a priority for the World Health Organization. S. Typhi possesses a viaB locus responsible for the biosynthesis of the Vi-capsular antigen, a significant virulence factor at the focus of developing improved prophylaxis for typhoid fever. Tissue culture experiments have demonstrated that S. Typhi wild-type capsule-expressing strain elicits less chemokine secretion than a viaB mutant. Calf experiments using the viaB mutant resulted in an increase inflammatory response. Osmolarity is one of the control signals that affect the biosynthesis of the Vi antigen. Under high osmolarity growth conditions of 300 mM and greater, Vi production is suppressed and S. Typhi is highly invasive. Studies reveal that the viaB mutant displays increased invasion towards intestinal epithelial cells. Our first objective was to implement direct and indirect methods to localize and detect Vi expression within intestinal epithelial cells and bovine Peyer's patch. The second objective was to compare the invasiveness between a viaB mutant, an ompR mutant, and S. Typhi grown under hyperosmolarity. We also measured the effects of these strains in eliciting inflammation in the calf model. We report that tviB was significantly up regulated intracellularly within T84 polarized cells. In the calf experiments, tviB was expressed at levels significantly higher in calf tissue following invasion compared to inoculum grown under Vi-suppressing conditions. Together, these results support the idea that the Vi capsular antigen is expressed after invasion of intestinal epithelial cells in vivo. We found that S. Typhi grown under high osmolarity, the viaB mutant, and the ompR mutant had increased invasion in polarized T84 cells and bovine ileal tissue. Fluid accumulation among Vi-deficient and Vi-suppressed strains was similar. The histopathology of the inflammatory lesions of the small intestine produced by the Vi-deficient and suppressed strains was quite comparable. Our data supports the notion that Vi-suppressed and Vi mutants of S. Typhi exhibit similar levels of increased invasion and inflammation, perhaps mechanistically through the inactivation of the Vi antigen.
87

Net Returns to Alternative Weaning Dates in Beef Cow-Calf Operations

Savage, Gregory Edward 01 May 2010 (has links)
There is sparse research literature in agricultural economics regarding early weaning as a potential alternative production/marketing strategy. The objective of this research is to estimate and analyze the impacts on net returns of alternative weaning dates for Tennessee cow-calf operations including alternative post-weaning treatments for calves.The Decision Evaluator for the Cattle Industry (DECI) simulation program was used for this study to produce outputs such as calf numbers, gender, and weights, other output including cow weights and body condition score, both at calving and at weaning, and pregnancy percentages. Forty-two simulations were run for average and summer drought weather, weaning at an average age of 135, 165, 195, 225, 255, and 285 days and selling at weaning or after a 60 or 90-day drylot backgrounding period. Prices for steers, heifers, and culled cows from 1995-2008 were taken from market reports. Costs were derived from University of Tennessee Extension Beef and Forage Budgets and USDA-NASS. The outputs from DECI were combined with prices to result in total revenues. Subtracting the costs of feed, interest, veterinary and medical, and marketing resulted in return to land, labor, management, and risk to the enterprise. The results of this study revealed that under average weather conditions in East Tennessee, marketing at weaning in November yielded the highest net return. Weaning in August and backgrounding for 60 days yielded the lowest net return with the base 90-cow herd.Under summer drought conditions, marketing at weaning in August resulted in the highest net return. Weaning in November and marketing after a 90-day backgrounding period yielded the lowest net return.Under the conditions used in this study, the only time early weaning makes economic sense is when herd size is increased for June or July weaning or under drought conditions when August (195 days) weaning and sale is optimal. Several limitations of this study imply that additional research is required on this topic before definite conclusions can be drawn.
88

Auswirkungen verschiedener Tränken auf Stewart-Parameter des Säuren-Basen-Haushaltes bei Kälbern mit experimentell induzierter metabolischer Azidose

Schwedhelm, Lea 25 November 2013 (has links) (PDF)
Das Ziel dieser Arbeit war es, den Einfluss unterschiedlich zusammengesetzter Tränken auf den Säuren-Basen-Haushalt bei Kälbern mit experimentell induzierter metabolischer Azidose zu untersuchen. Bei gesunden Kälbern konnte nachgewiesen werden, dass die Fütterung von milchbasierten ORL mit einer [SID3] ≥92 mmol/l eine Erhöhung der Plasma-[SID3] zur Folge hat (BACHMANN et al. 2009b) und damit eine alkalische Wirkung auf den SBS. Zu prüfen galt die Hypothese, ob es bei Kälbern mit experimentell induzierter metabolischer Azidose zu einem stärkeren alkalisierenden Effekt nach Gabe einer Tränke mit einer hohen [SID3] kommt. Bessere alkalisierende Eigenschaften einer Tränke könnten potentiell genutzt werden, um den Genesungsprozess von Kälbern mit metabolischer Azidose zu beschleunigen. Material und Methoden Zur Verfügung standen zwölf Kälber der Rasse Holstein-Friesian im Alter von weniger als vier Lebenswochen. Unter Verwendung von in der Literatur beschriebenen Induktionsprotokollen konnte per Infusion bei jeweils sechs Tieren eine manifeste hyperchlorämische Azidose und bei weiteren sechs Kälbern eine D-/L-Laktatazidose ausgelöst werden. Die Tiere wurden im Anschluss mit Milchaustauscher, wasser- oder milchaustauscher-basierter oraler Rehydratationslösung getränkt bzw. blieben im nüchternen Zustand. Zur Bestimmung von Stewart-Parametern des Säuren-Basen-Haushaltes im Plasma wurden nach einem festgelegten zeitlichen Schema vor und nach Induktion sowie vor und nach der Tränkegabe venöse Blutproben entnommen. Ergebnisse Bedingt durch die Einleitungsprotokolle war die Interpretation der Messergebnisse durch den starken Anstieg des Plasmavolumens bedeutend erschwert. Die eingesetzten Induktionsprotokolle sind nicht für Untersuchungen des Säuren-Basen-Haushaltes bei Kälbern nach unterschiedlicher Fütterung geeignet. Aus diesem Grund kann die aufgestellte Hypothese, dass die Verabreichung von milchaustauscher-basierter ORL zu einer besseren alkalischen Wirkung bei Kälbern mit metabolischer Azidose führt, anhand der vorliegenden Ergebnisse weder abgelehnt noch bestätigt werden. Einige Untersuchungsergebnisse zeigten positive Effekte auf Parameter des SBS bei Kälbern, denen eine Tränke verabreicht wurde, im Vergleich zu nüchternen Tieren. Diese Parameter waren die Plasma-D-Laktatkonzentration, die Strong Ion Difference [SID3] und [SID4] und ionisiertes Calcium [Ca2+]. Die Effekte waren nicht auf eine bestimmte der drei eingesetzten Tränkevarianten zurückzuführen. Weiterhin konnte gezeigt werden, dass ein quadratischer Zusammenhang zwischen der berechneten Variable Strong Ion Gap [SIGAlb/TP] und den gemessenen D-/L-Laktatkonzentrationen im Plasma besteht. Dies könnte zukünftig genutzt werden, um Faktoren zu etablieren, welche die Ableitung der Plasma-D-/L-Laktatkonzentration bei durchfallkranken Kälbern mit ZNS-Symptomatik aus gängigen Parametern ermöglicht, ohne die Laktatkonzentration direkt messen zu müssen. Schlussfolgerungen Für zukünftige Untersuchungen dieser Art wäre ein Induktionsprotokoll wünschenswert, das sowohl eine metabolische Azidose bei gleichzeitiger Dehydratation der Kälber vereint und so die metabolischen Bedingungen durchfallkranker Kälber simuliert. Die Gabe von ORL als direkte Einmischung in Milch bzw. MAT wird kritisch betrachtet. Ein negativer Effekt bei der Gabe von MAT-basierter ORL konnte bei diesen Untersuchungen auf keinen der bestimmten Parameter des SBS im Vergleich zu den anderen Tränkezusammensetzungen festgestellt werden. Klinische Nebenwirkungen Bei dieser Untersuchung traten nach der mehrfachen Infusion von D-/L-Laktat unerwartete Nebenwirkungen auf. Die Verabreichung führte zu starken Irritationen der Vena jugularis externa und zu Ödembildungen. Erhöhte D-Laktatkonzentrationen werden beim Menschen und verschiedenen Tierarten als Marker für traumatische Prozesse, Ischämie, Diabetes, gastrointestinale und neurologische Störungen diskutiert. Die weitere gezielte Untersuchung des Einflusses der wiederholten oder anhaltenden Einwirkung von D-Laktat auf Epithelzellen könnte nach den vorliegenden Untersuchungsergebnissen einen weiteren Anhaltspunkt für die Aufklärung der genauen pathologischen Mechanismen des D-Laktates bieten.
89

Kombinuoto startinio pašaro „Milaflo“ įtaka veršelių auginimo spartai / The influence of composite start feed „Milaflo“ for growing intensity of calf’s

Urbonas, Remigijus 27 March 2006 (has links)
Health and productivity of grown-up animals highly depends on technology of breeding of calf’s. It‘s very important, that calf’s aged 3-4 months shouldn‘t fix diseases of digestive and airways systems. The main aim of this work was to determine influence of composite start feed „Milaflo“ to the intensity of breeding, development of internal organs and wellness of calf’s. Summing-up the result conclusions are provided as follows: organism of heifers develops faster, when during the period of feeding with milk combined start feed was used; composite start feed „Milaflo“ meets all zootechnical requirements and grants intensive growth of calf’s during feeding with natural milk and other crops without any negative reaction to wellness of calf’s; during test period in ŽŪB „ Pauliukai“, daily gain of calf’s which were feeded with „Milaflo“ contained 778,3 g/ per day, while ones feeded with standard composite feed - 713,9 g; during test period in Center of Practical Education of LVA daily gain of control group calf’s contained 708,9 g, heifers, which were feeded with additive „Milaflo“ and powder of conditioned milk – 752,2 g, heifers which were feeded with additive „Milaflo“ and natural milk – 966,7 g; use of composite start feed „Milaflo“ has no negative reaction to morphological composition of blood; highest efficiency of composite start feed concerning the development of great prestomach was noted during week 3 - 4.
90

The assessment of Replacement Heifer Production Efficiencies through Residual Feed Intake and Key Hormone Profiles

Smith, Brock Andrew 04 January 2013 (has links)
Biological factors regulating feed efficiency were investigated in replacement beef heifers to establish factors that differ between efficient and less efficient animals. Feed efficiency, measured as residual feed intake (RFI) adjusted for body ultrasound measurements, was determined in forty-seven cross-bred heifers. Reproductive differences between efficient (low RFI) and less efficient (high RFI) heifers were examined. Low RFI heifers had an earlier age at both sexual maturity (P=0.08) and conception (P=0.08), and delivered heavier calves (P=0.006). The potential of fecal progesterone metabolites (FP4M) as an indicator of sexual maturity was examined. Measurements of FP4M present a promising non-invasive alternative technique for determining the onset of sexual maturity. A subset of 36 heifers was used to determine if plasma triiodothyronine (T3) concentrations could be used to predict feed efficiency. Triiodothyronine concentrations a correlation of 0.58 (P=0.001) to those from a quadratic prediction model of RFI in heifers sampled as yearlings. / Research into reproductive characteristics associated with residual feed intake, and to determine the effectiveness of the thyroid hormones as a screening tool for feed efficient animals. / OMAFRA (Ontario Ministry of Agriculture, Food, and Rural Affairs) through the Farm Innovation Program, Agriculture Canada through the Growing Forward Project, the Canadian Cattlemen’s Association through the Beef Cattle Research Council, and the Ontario Cattlemen’s Association.

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