School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemOestrogens, isoflavones and the oestrous cycle of the ewe( 1972)The experimental work presented in this Thesis was carried out while the author was a recipient of a Commonwealth Post Graduate Scholarship. The supervision of the experimental work in Chapters 3 to 6 inclusive was delegated to Mr. I.A. Cumming and his willing help, advice and collaboration is gratefully acknowledged. Material contained in these Chapters was obtained from experiments carried out at the S.S. Cameron Laboratory, State Research Farm, Werribee, Victoria. Chapters 7 and 8 report results of Field Trials conducted in collaboration with Mr. J.M. Obst and the Officers of the S.A. Department of Agriculture, and Drs. R.J. Lightfoot and J.F. Smith and the Officers of the W.A. Department of Agriculture, respectively. The experimental programmes in the latter two chapters were mainly financed by the Australian Wool Board Funds allocated to my supervisor, Dr. J.R. Goding. The material presented in Chapters 4, 6 and 8 has been presented to the meetings of the Australian Society for Reproductive Biology (ASRB), 1971, and the Fourth Asia and Oceania Congress of Endocrinology, N.Z., 1971. The abstracts are listed at the end of the Preface. The general facilities of the State Research Farm, Werribee were made available for these studies and the author wishes to thank the Officer in Charge of the S.S. Cameron Laboratory, Dr. P.D. Mullaney and the past Acting Officer in Charge, Mr. A.D. North. Thanks must also be offered to Mr. J.B. McPherson, Manager of the State Research Farm and his staff for assistance in the purchase, feeding and general management of the flocks of sheep used for these studies. I would like to acknowledge the help and support received from my supervisor, Dr. J.R. Goding during the past two years, but particularly to thank him for his invaluable assistance and encouragement during the preparation of this manuscript. Dr. J.M. Brown and her technical assistants Misses J. Fratantaro and E. Renden generously performed the majority of the LH assays. The progesterone assays were done with the assistance of Miss B. Sinnott and under the guidance of Mr. J.M. Obst of the S.A. Department of Agriculture. Mr. G.J. Gyory of the Victorian Department of Agriculture carried out the isoflavone analyses, and Mr. R. Jardine also of the Victorian Department of Agriculture carried out the statistical analyses. Most of the experimental procedures required labour 24 hours a day and this was willingly provided by Agricultural Officers of the Victorian Department of Agriculture. My thanks and appreciation to Messrs. R.W. Baxter, T. Howard, W.B.H. McGregor, A.W. Makin, R.A. Parr and A.H. Williams. Assistance for these experiments was also given to me by my colleagues, Dr. M.A.deB. Blockey, Mr. L.P. Cahill, Dr. M. Cain, Mr. J. Cerini, Mrs. M.E.D. Cerini, Mr. W.A. Chamley, Mr. I.A. Cumming, Miss M.A. Curtis and Miss B.J. Mole. Invaluable technical assistance was given by Mesdames D. Baxter, M. Perry and Misses J. Fratantaro, E. Renden and E. Wilson. A special thank you must be offered to Mr. P. Langdon for the outstanding technical assistance and generous help which made so much of this work possible. The photographic work was done by Mr. W. Douglas and Mr. D. Rizzoli. Mrs. H. Constable typed all the drafts of the Thesis and the final manuscript was typed by Mrs. Adele Dowling. My thanks to all who have assisted me over the last two years.
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ItemAn evaluation of the role of extension in the Australian pig industry( 1978)Australian agriculture is adjusting to changes in technology, economic circumstances and markets. Extension services as much as the producers' need to change in response to changing industry needs, market trends and consumer demands. There has been much discussion on the problems that these changes present for extension, but none on the basis of empirical research or social science theories. A research program was developed to define the changes taking place in the structure and organisation of the Australian pig industry, and to identify the implications of these changes for pig producers and for extension agencies such as State Departments of Agriculture. The conclusion drawn from the review of the industry situation and from a Delphi survey of 10 experts in the pig industry was that the industry will become more technical and commercialised requiring continual adaptation by the producers to technical and economic changes in order to maintain and increase production efficiency. The survey results showed that a degree of assistance from research and extension was expected by producers to help them maintain and improve production efficiency. Based on the Theory of Personal Constructs, Kelly (1955) an interactive psychological testing procedure known as the Repertory grid was used to record producers' and extension officers' perceptions of each other and of extension services. Twenty pig industry officers, 16 non extension users, 20 extension users and 16 large commercial producers were interviewed. Separate analyses were carried out on the grids of individual subjects, providing profiles of constructs typically used by the subjects in relating to and evaluating people. The results clearly identified the constructs which farmers used in relating to extension advisers and advice. In general, all groups of subjects tended to stereotype people with whom they associated. Combination of both the results within subject groups revealed evidence of commonality within and between the groups in their perceptions. The extension officers saw themselves as progressive and useful while a large number of the producers saw them as theoretical and irrelevant. Extension users held favourable attitudes towards professional agricultural advisers, while large commercial producers and non extension users criticised them on the grounds that they were difficult to communicate with and lacking practical experience. As a group, extension officers were not aware of the questioned relevance of their advice nor of the difficulty experienced by producers in communicating with them. Owing to their practical background and shared experiences, all producers saw other producers as useful and as the most relevant source of advice. The roles they expect him to perform and the characteristics that producers expect from a professional extension adviser have been identified and their implications for the extension officer are discussed. The most obvious implications of the findings are that extension advisers fail to establish the relevance of information within the farmers' context of what is relevant. Based on the findings of the research the theory is proposed that extension programmes will be most successful when producers and extension workers share common perceptions of relevant problems. A philosophy and practice of extension is proposed to meet the farmers' own perception of needs. The interpretation of the results in terms of Personal Construct theory leads to the development of the model of human behaviour, that is, "man as an actor" instead of "man as something being acted upon". A philosophy of extension is developed based on the belief that extension can only be successful if it provides what farmers want. The philosophy states that extension should provide a helping role by facilitating, developing and supporting "man the actor" without dominating or controlling his actions. A practice of extension operating within the boundaries of the proposed new philosophy is developed from the helping relationship model of Carkhuff (1969). The goals of extension are defined as exploration, understanding and action which lead directly to the need for skills which are defined as the "interface skills" of attending, responding, personalising and initiating. The need for and the nature of extension training to provide extension officers with "interface skills" is discussed.
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ItemEffects of some management factors on sheep and wool production( 1970)It is difficult to be precise about the importance of the contributions made by the many people involved in this work. On a government research station and on private farms, field experiments inevitably involve many people. However, in each chapter presented in this thesis I made a major contribution in the planning, supervising and conducting of the experiment and in preparation of the results for publication. Where authorship has been shared, this is indicated at the beginning of each chapter. Some indication of the relative importance of contributions to this work is as follows:- Chapter I: The experiments were done on two sites, and at one of them Katamitite) I was directly responsible for the work. Chapters II, III: This work undertaken jointly with Mr. J.G. Bath, Chapters IV, V: This work was my responsibility. Chapter VI: The observations on sheep were my responsibility whereas those on pastures were the responsibility of Mr. J. Avery and Mr. I. Cameron. I prepared the manuscripts for chapters I to V and contributed to the preparation of that for chapter VI.
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ItemHybridization between Lycopersicon esculentum mill. and L. peruvianum (L.) mill( 1979)The incompatibility barrier between L.esculentum and L.peruvianum was shown to be incomplete and to vary for different L.peruvianum strains. The frequency of hybrid production was not increased when both species were grafted on to each other before cross-pollination. Pollinations with L.esculentum pollen followed immediately by L.peruvianum pollen and pollinations with irradiated L.peruvianum pollen also did not increase the frequency of hybrid production. However, using tetraploid L.esculentum as the female parent gave slight increases in the frequency of hybrids produced compared with the cross, 2n L.esculentum x 2n L.peruvianum. Cytological studies of the parent species and their hybrid at various ploidy levels demonstrated close cytological similarity of L.esculentum and L.peruvianum chromosomes and indicated there may possibly be as high a level of chromosome pairing in the diploid hybrid as in both diploid gents. The diploid and tetraploid hybrids were shown to have very high levels of pollen fertility and the triploid to have a much lower level of pollen fertility due probably to chromosome imbalance after meiosis. The results indicate that it would be possible to select within L.peruvianum for strains having compatibility with L.esculentum. It would be most useful to be able to hybridize readily the species at the diploid level because of regular chromosome pairing in the diploid hybrid and a high level of pollen fertility. While the use of tetraploid L.esculentum would slightly increase the frequency of hybrid production, the pollen fertility of the hybrids is low and in a system of back- crossing to diploid L.esculentum, there would be incompatibility between plants having different chromosome numbers