• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 66
  • 33
  • 27
  • 15
  • 4
  • 3
  • 3
  • 3
  • 2
  • 1
  • Tagged with
  • 170
  • 34
  • 27
  • 24
  • 24
  • 20
  • 19
  • 17
  • 17
  • 14
  • 14
  • 14
  • 12
  • 12
  • 12
  • 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.

Behavioural differences between and within retriever breeds

Brodd, Louise January 2016 (has links)
The retriever breeds have the same origin and have long been used as a gundog for hunting of game, mostly birds. However, recently the retriever breeds have become a popular pet and show dog. This have affected the breeding of the dogs as the same traits are not bred for a gundog and a pet or show dog. Breeds as the Labrador retriever consists of a field- and common-type. The aim of this study is to investigate any differences between and within five of the retriever breeds in behaviours as retrieving, search and game reaction. 64 dogs undergoing the field trial Description of Function- Retriever was video recorded and scores from 430 dogs that have undergone field trials was obtained. Both differences between and within breeds were found when analysing both the videos and scores. In the video analysis, the Flatcoated retriever showed the most retrieving behaviours and was the most passive. The Nova scotia duck tolling retriever was in both the video and score analyses the most active breed. The Labrador retriever scored high in game reaction. The field- and mixed-types had almost always higher scores in behaviours linked to hunting, compared to the common-type. This supports findings that recent selection in breeding have a larger effect on behaviour than the origin uses of the dogs.

Across breed genomic evaluation in cattle

Brown, Alexandra January 2017 (has links)
Genomic evaluation techniques have been a huge success in the dairy cattle industry, as they allow accurate enough estimation of breeding values at a young age to allow selection decisions to be made at an earlier stage, thereby increasing the rate of genetic progress per annum. The success of genomic selection techniques relies on the existence of linkage disequilibrium (LD) between markers and quantitative trait loci (QTL) across the population of interest; LD persists across larger distances within breeds than across breeds. Therefore, most success so far has been for selection within breeds, but the industry is keen for “across breed” evaluations to be developed, both in a multi-breed scenario which would allow evaluations for breeds that are numerically too small to carry out evaluations within breeds, and also for the evaluation of crossbred animals. This thesis investigates the potential for applying genomic selection techniques in both the multi-breed and crossbred scenarios. Chapter 2 examines the potential for a multi-breed reference population to improve the accuracy of genomic evaluation for a numerically small breed, for a range of production and non-production traits. The results provide evidence that forming a multi-breed reference population for two closely related breeds (Holstein and Friesian) results in a higher accuracy of GEBVs for the smaller breed, particularly when more phenotypic records are added via the single-step GBLUP method, and when a higher density SNP chip is used. Chapter 3 examines the crossbred scenario, whereby GEBVs are calculated for crossbred individuals based on a crossbred reference population. The population used for analysis was a highly crossbred African population, and GEBVs were calculated for three groups of animals chosen according to whether they had a high or low proportion of imported dairy genetics. Accuracy of prediction was higher than expected, and provided proof of concept for applying genomic selection techniques in crossbred African cattle populations. Chapter 4 investigates the potential for using novel SNPs derived from sequence data in order to estimate genomic relationships across cattle breeds, deploying data from two closely related breeds, Fleckvieh and Simmental, and a further distant European breed, the Brown Swiss. Novel SNPs were selected from sequence based on their putative impact on the genome, with impacts being inferred by SNP annotation software snpEff. Results showed that genomic relationships calculated using novel SNPs have a high correlation with genomic relationships calculated using SNPs common to the Illumina BovineHD SNP chip, though between-breed correlations were lower than those within breeds. The results presented in this thesis demonstrate that utilising a multi-breed reference population can improve the accuracy of prediction for a numerically small breed, and that genomic prediction of highly crossbred individuals is also feasible. However, differences between breeds and also types of crossbred animal suggest that no one solution can be used for all across-breed evaluations, and further research will be needed to allow commercial implementation in further populations.

Holšteinizacijos įtaka karvių pieno sudėčiai ir kokybei / Infuence on holstein breed on the milk composition and quality

Buterlevičiūtė, Daiva 18 June 2013 (has links)
Darbo tikslas yra įvertinti holšteinų veislės įtaką karvių pieno sudėčiai ir kokybei. Visi tyrimų duomenys įvertinti naudojant „R“ statistinį paketą Gyvūnų veislinės vertės tyrimų ir selekcijos laboratorijoje. Pagal gautus tyrimų rezultatus ir juos apibendrinusi, galiu teigti, kad tiriamoje karvių bandoje didėjant holšteinų veislės genų daliai, mažėja karvių pieno primilžis, nes nustatytas neigiamas ryšys ir korealiacija statistiškai patikima. Pieno riebumas taip pat mažės, nes ryšys tarp jų nustatytas neigiamas. O pieno baltymingumas didės. Tačiau pieno kokybė, pagal somatines ląsteles, prastėja, nes nustatytas ryšys buvo teigiamas ir koreliacija statistiškai patikima. / The aim of Master work is to valuate Lithuanian cows productivity and milk composition considering the blood dimensions of holstein breed. All data had been made through statistical analysis by EXCEL computation as well as by statistical package „R“ in the LVA Laboratory of Animals Research of Breeding Worth and Selection. In accordance with the results of the studies and received responses to them, I can say that part of the decline as the holšteinų blood of cows ' milk, because of the negative linkage Estimator and korealiacija statistically reliable. The content will also decline, because of the negative linkage between them. While the increase in the milk baltymingumas. However, the quality of the milk, the somatic cells, degraded, because the connection was positive and statistically reliable correlation between the.

Characters' Views and Perception : Hybridity and the Westerners in Two Indian Novels by Arundhati Roy and Salman Rushdie / Karaktärers synsätt och uppfattning : Hybriditet och västerlänningar i två indiska romaner av Arundhati Roy and Salman Rushdie

Petersson, Pernilla January 2013 (has links)
In the two novels, The God of Small Things by Arundhati Roy and Midnight’s Children by Salman Rushdie, characters show that their preconceptions and encounter with the Westerners play a big role in how they view Westerners and/or Indians who have adapted to or grown up with the Western lifestyle. Due to Roy’s family being a group of “Anglophiles” and liking the British, they see Sophie Mol being half-Indian as positive. Padma, Saleem’s partner in Rushdie’s novel, on the other hand, is less familiar with the British and therefore has problems accepting that Saleem is half-English. This difference between how the two families view the half-breeds, Sophie Mol and Saleem, can also be connected to the long history of colonialism, where Roy’s family has been trained to like the British, whilst Padma was born after India’s independence and was not trained to like the former colonists. Similarly, Chacko is being more accepted for his adaptation to English ways by his family than Aadam is by his family. However, Chacko is not accepted by the English, where he feels that he belongs, which makes both Chacko and Aadam feel “rootless” in their home culture. It is through these preconceptions and different encounters that characters view and believe that there is a difference in behaviour between the Indian and Western women, and that Westerners have a need to have higher status than the Indians. This essay shows that Indians have different views depending on their knowledge, lack of knowledge, interest or lack of faith in the West.

Three Essays on U.S. Agriculture under Climate Change: Active Engagement in Mitigation and Adaptation

Zhang, Yuquan 2011 December 1900 (has links)
This dissertation investigates: (1) the implications of including high-yielding energy sorghum under the Renewable Fuels Standard (RFS2) program; (2) the effects of RFS2 with and without projected climate change scenarios on U.S. agriculture; (3) the spatial distribution of cattle breeders in Texas to quantify how climate factors influence cattle breed selection. In the RFS2 energy sorghum work, the ability of the agriculture sector to meet the fuel requirements of RFS2 is examined with and without energy sorghum being a possibility using an agricultural sector model. The results show that energy sorghum would be a valuable contributor that would be used as a feedstock producing over 13 billion gallons per year of cellulosic ethanol. Without the presence of energy sorghum it is found that switchgrass serves as the major cellulosic ethanol feedstock. Findings also indicate that the presence of high-yielding energy sorghum does relax commodity prices and export reductions except for grain sorghum as energy sorghum competes with grain sorghum production. In addition, the results show that the introduction of energy sorghum has minimal effects on GHG mitigation potential in the agricultural sector. In the RFS2 and climate change research, the analysis shows that climate change eases the burden of meeting the RFS2 mandates increasing consumer welfare while decreasing producer welfare. The results also show that climate change encourages a more diversified use of biofuel feedstocks for cellulosic ethanol production, in particular crop residues. In the cattle breed research, summer heat stress is found to be a significant factor for breed selection: positive for Bos indicus and negative for Bos taurus and composite breeds. The estimation results also indicate a price-driven trade-off between Bos taurus and Bos indicus breeds.

Effect of initial stand spacing and breed on dynamic modulus of elasticity of Pinus radiata

Waghorn, Matthew J. January 2006 (has links)
Wood stiffness or modulus of elasticity (MOE) is one of the most important wood properties for solid timber applications, and as such, the efficacy of wood use, especially for structural timber is strongly related to MOE. MOE in Pinus radiata is highly variable and poorly understood. In this study, the effect of initial stand spacing and breed on outerwood MOE and the vertical distribution of MOE of Pinus radiata was assessed. Understanding positive or negative influences of growth caused by initial stand spacing and genetic material on MOE is appealing because it could enable us to better comprehend how forest growers could adapt silvicultural operations to the demands of wood processing. Physical characteristics of different breeds and propagation methods of Pinus radiata were assessed at a variety of initial stand spacings. Stem diameter, crown height, stem slenderness and branch size were all heavily influenced by stand spacing. Breed had a marginally significant influence on diameter and stem slenderness. Internode length was not affected by stand spacing, but showed sizeable differences, especially between the long internode 870 breed and the remaining growth and form (GF) breeds. Outerwood MOE was significantly (P<0.0001) influenced by stand spacing and breed, but not their interaction (P>0.05). MOE scaled positively with stand spacing. MOE increased by 39% from 5.4 GPa at 209 stems ha-1 to 7.5 GPa at 2551 stems ha-1. The majority of this increase (33%) occurred between 209 and 835 stems ha-1. Physiologically aged cuttings of greater maturation status exhibited greater MOE, with the three-year-old cuttings being stiffer than the one-year-old cuttings, seedlings from the 870, 268 and 850 series, by 15, 17, 22 and 27%, respectively. Stem slenderness exhibited the strongest significant (P<0.0001) relationship with MOE (r2=0.49), followed by green crown height (r2=0.46) and diameter (r2=0.44). Stem slenderness and green crown height had a direct influence on MOE that explained 53% of the variance in MOE. MOE was also significantly (P<0.0001) influenced by spacing and breed when using the resonance technique to assess whole stem MOE. The vertical distribution of MOE showed that the lowest portion of the stem (bolt 1) was approximately 30% less stiff than bolts 2 and 3. After the greatest MOE value had been obtained at bolt 3, MOE gently declined to the top of the measured stem. Variation of MOE within trees was significant (58%) at the high stockings of 1457 and 2551 stems ha-1, but somewhat lower (36%) at the lower stockings. The 870 breed was approximately 8% and 16% stiffer than the 268 and 850 breeding series respectively, across all stockings, with the three-year-old cuttings being 7% stiffer than the one-year-old cuttings. At stockings of 481 stems ha-1 and less, the proportional height at which MOE was greatest within a tree was between 25% and 50% of stem height. At stockings above 481 stems ha-1 the proportional height at which maximum MOE was obtained was between 15% and 40% of stem height. Bolt slenderness was found to be the most significant factor impacting on MOE of the bolt. Regression of critical buckling height against diameter at ground level yielded a scaling exponent of 0.55, which was lower than the scaling exponent of 0.67 predicted with constant density-specific stiffness. There was a tendency for some bolts with lower mean diameter to display significantly higher safety margins than bolts with higher mean diameter, suggesting that the largest bolts, which occur at the base of tree, are the point of most likely critical failure.

Leistungsprüfung bei Schweinen

Gschwender, Felicitas, Milich, Andrea 24 August 2010 (has links) (PDF)
Im Prüfjahr 2009 erhielten 842 Tiere (davon 492 Eber der Deutschen Landrasse) einen Prüfabschluss. 39 Eber mit hervorragender Eigenleistung wurden durch den Mitteldeutschen Schweinezuchtverband e.V als Besamungseber angekauft. Der Jahresbericht dokumentiert den Prüfablauf und die Prüfergebnisse. Bei den geprüften Rassen wurden u.a. die Mast- und Schlachtleistung sowie die Fleischqualität untersucht. Die Durchführung der Leistungsprüfung erfolgt praxisnah in Gruppen mit elektronischer Einzeltiererkennung und tierindividueller Erfassung des Futterverzehrs. Es erfolgt eine kombinierte Eigenleistungs-, Geschwister- und Nachkommenprüfung mit hohem Anteil Ebereigenleistungsprüfung zur züchterisch effizienten Nutzung der Prüfkapazitäten. Grundlage der Prüfung, die seit 1995 im Lehr- und Versuchsgut Köllitsch durchgeführt wird, sind die bundeseinheitlichen »Richtlinien für die Stationsprüfung auf Mastleistung, Schlachtkörperwert und Fleischbeschaffenheit beim Schwein (Geschwister- und Nachkommenprüfung)«, die vom Zentralverband der Deutschen Schweineproduktion e.V. herausgegeben werden.

The natural history of periodontal disease in beagle dogs gingival inflammation, debris, birfurcation [sic] involvement, and roentgenographic bone loss : thesis submitted in partial fulfillment ... periodontics ... /

Grove, Thomas K. January 1975 (has links)
Thesis (M.S.)--University of Michigan, 1975.

Properties of flow through the ascending aorta in boxer dogs with mild aortic stenosis momentum, energy, Reynolds number, Womersley's, unsteadiness parameter, vortex shedding, and transfer function of oscillations from aorta to thoracic wall /

da Cunha, Daise Nunes Queiroz, January 2009 (has links)
Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 113-121).

Verifying parentage and gender of domestic dog conceptuses using microsatellites

Steckler, Daniela 21 December 2010 (has links)
Parentage testing in the domestic dog is finding increasing application for dog breed registries as well as in research. The aim of parentage verification is the correct assignment of both parents to the offspring. For accurate parentage verification informative microsatellite markers have to be identified. More powerful models to study artificial insemination in bitches will be possible if the paternity and gender of early dog conceptuses can be determined. The amelogenin gene locus has been used in bovine day six to day seven embryos for early gender determination but no research has been done on early conceptuses of the domestic dog. The aim of the current study was to establish an accurate method for parentage and gender determination from domestic dog conceptuses during early pregnancy in a multi-sire insemination trial. Semen from 10 male dogs was used in each of 12 females for artificial insemination. Blood and uterine tissue for DNA extraction was collected from males and females, and embryonic material was collected after ovariohysterectomy between 16 and 30 days after the onset of cytological dioestrus. Twenty-three microsatellite markers were used for parentage verification, and the amelogenin gene locus for gender determination. Mean observed heterozygosity, mean expected heterozygosity (HExp), and mean PIC were high (0.6753, 0.6785, and 0.628, respectively). There were 66 conceptuses. In two, neither parentage nor gender could be established because their tissue samples were contaminated. Parentage could be assigned by CERVUS 3.0.3 in 42 out of 64 of the cases (66%) without difficulty. Another 33% of the cases (21 out of 64) could be resolved using the number of exclusions, LOD scores or manual verification of genotyping errors. In one conceptus, paternity could not be established because its sire may have been either of two siblings. The gender of the female and male dogs was successfully confirmed using the amelogenin gene locus. The gender of the conceptuses was determined using the amelogenin gene locus (50% male, 50% female) but not confirmed by another method of gender determination such as karyotyping. As shown in the current study, the panel of 24 microsatellite markers used provides high information content suitable for parentage verification in multi-sire litters, as well as gender determination of early conceptuses. / Dissertation (MSc)--University of Pretoria, 2010. / Production Animal Studies / unrestricted

Page generated in 0.0428 seconds