Bacteriological survey of the fish pathogens in Greek mariculture between 1994- 1997 was followed by analysis of prevalence in sea bass, sea bream, sharpsnout bream and common Dentex and discussion of the impact of various fish pathogens. In addition antibiotic resistance profiles and frequencies were studied using quantitative antibiogram and MIC analysis for the two most commonly used antibiotics Oxolinic acid and Oxytetracycline and clinically relevant MIC breakpoints were extrapolated for different fish species and main fish pathogens. The kinetics of the above antimicrobials were analysed in eight experiments where two fish species namely sea bass and sea bream as well as two water temperatures were employed. Muscle, liver, serum, skin samples were analysed by two HPLC methods and two bioassay methods were developed. The relative importance and significance of these findings was evaluated in the general context of pharmacokinetic studies in fish. Kinetic data were compared to clinical data and practical implications were evaluated. Issues like antibiotic resistance and its implications, the implications of residues and resistance in human health and the environment were analysed in order to put this study in context. Conclusions tackled important aspects of antimicrobial chemotherapy and future work was suggested.

The thesis examined the effects of climatic change on livestock production within Scotland. In order to achieve this, a systems model of the dairy, beef and sheep enterprises was developed. Climatic change primarily affects livestock production through its effects on forage production. Under climatic change, the model predicted that the length of the growing and grazing season will increase with the extensions occurring at both ends of the season. Relative to current climatic conditions elevated CO2 concentrations coupled with the associated changes in climate resulted in an enhancement in harvestable dry-matter yield that ranged from 20% to nearly 60% and increases in the percentage of white clover in the harvestable material by up to 126% In general, global warming is predicted to increase forage and livestock production within Scotland. However, the location of the site is also important in determining the effect of climate change as the magnitude and, in some cases, the directions of the changes varied between sites. The effects of climate change were also dependent on the actual level of changes in temperature. In addition, there were interactions between CO2 concentration and both temperature and rainfall, as well as interactions between temperature and rainfall. Although the three enterprises showed similar trends in their response to climate change, there were differences in the magnitude of the response as well as differences in the factors that resulted in significant changes. There were also differences in the response of the grazed and the ungrazed swards. This underlines the complexity of the interactions and the difficulty of extrapolating the results to other locations and to other levels of climatic conditions. The advantage of developing a model is that all these complex interactions can be captured and potentially the site - specific consequences of climate change on forage and livestock production predicted.

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Improving efficiency within the agricultural industry is vital to maintain the food demands of the increasing population, as well the current preference for a more protein rich diet. One avenue for addressing these issues is to study animal-based growth to determine if the efficiency of the production system can be improved by increasing lean muscle mass. The aim of this thesis is to provide an alternative exploration to experimental work to provide an insight into how muscle metabolism in pigs is altered by the administration of a beta-agonist which induces muscle hypertrophy. This will be incorporated into a wider body of work to determine specific pathways to target for improving feed conversion efficiency, contributing to the necessary research into global food security. We begin by compiling a selection of statistical methods to analyse muscle microarray data, which enables the identification of a selection of genes whose expressions are altered by the exposure to a beta-agonist. These differentially expressed transcripts are then grouped via a k-means algorithm, with log likelihood and the Bayesian Inference Criterion calculations providing an optimal selection of clusters. This results in selecting a group of 51 transcripts and partitioning them into 9 clusters, and identifying several pathways which appear key to the regulation of muscle metabolism in the presence of beta-agonist. We have proceeded to incorporate this information into a mathematical model for glycolysis and the TCA cycle, in an effort to analyse biological hypotheses about how the promoters work. The equations describe the concentrations of metabolites within the cytosolic and mitochondrial compartments of a cell using mass balance ODEs. An initial model is presented, which is then increased in complexity, to keep up with developments in the experimental side of the overarching project. We make use of a selection of methods to analyse the model in an attempt to determine the effects that the different parameters cause. Through steady state analysis, we determine parameter ranges which permit positive steady states. In finding these regions, we also determine the existence of time dependent solutions, which occur when critical values of certain parameters are exceeded, and result in the build up of specific metabolites. We use asymptotic analysis to generate approximate solutions when steady states do not exist. The model parameters of most interest are those which were identified through the microarray work, namely the upregulated transcripts of PCK2 and those within the serine synthesis pathway, the control mechanism for the first half of the TCA cycle, the proportion of GTP producing enzyme from the second half of the TCA cycle, and the flux into the glycolytic pathway. We find that critical values for the glycolytic flux, and the GTP production parameter exist, determining whether the model lies within the steady state regime. In a large number of cases, the parameters we choose to represent the beta-agonist case push the system into the time dependent state. The model does not exhibit any interesting behaviour when the parameter controlling the PCK2 pathway is studied, indicating that initial intuition of the key controlling reaction mechanisms were incomplete. Whilst there are shortfalls in the model, which highlight areas for investigation, the system is set up for validation and parameter fitting when appropriate experimental data become available. We have been able to determine specific metabolic pathways within the cell which may be of significance to improving feed efficiency.

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Der Tierzuchtreport 2014 liefert, überwiegend in Zeitreihen, für die Tierarten Rind, Schwein, Pferd, Schaf und Ziege umfangreiche Daten zu Bestandsentwicklung, Rassenstruktur und Leistungen. Weitere Tierarten werden im Überblick dargestellt. Der Report enthält außerdem ein umfangreiches Adressenverzeichnis aller mit der Tierzucht befassten Organisationen. Infolge Veränderungen im Tierzuchtrecht erscheint der Report in dieser Form letztmalig.

Für einen sicheren Herdenschutz in Gebieten mit frei lebenden Wölfen ist der Einsatz geeigneter Elektrozäune unabdingbar. Der Einsatz von Herdenschutzhunden ist als zusätzliche Maßnahme zu erwägen. Der Umgang mit Herdenschutzhunden erfordert Sachkenntnis und Verantwortungsbewusstsein. Die Broschüre erläutert Unterschiede zum Hütehund, beschreibt Grundlagen der Sozialisierung und stellt die wichtigsten Rassen vor. Im zweiten Teil werden Empfehlungen für eine übersprungsichere Elektro-Umzäunung gegeben, die mit vertretbarem Zeitaufwand aufgebaut werden kann.