Agriculture and Food Systems - Theses

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    Beef-cattle production in the Western District of Victoria : technical and economic relationships between beef cattle and sheep
    Wills, I. R ( 1965)
    Sheep-and-wool production and beef-cattle production are combined on many grazing properties in the Western District of Victoria. In the past beef cattle have generally been regarded as less profitable than sheep as a sole enterprise on a per-acre basis. In previous surveys it has been found that graziers believe that sheep and beef-cattle complement one another in a variety of circumstances because of the different effects of the two types of animal on pasture. It has also been found that sheep and beef cattle on grazing properties are frequently supplementary with respect to labour. The thesis has two main objectives. First it investigates whether the currently available analytical models based on static economic theory are adequate to solve problems of resource allocation between sheep and beef cattle grazing the same pasture. Second, it investigates whether many graziers carry beef cattle partly or solely to satisfy goals other than profit maximisation. The method of achieving the first objective was to compare the static economic theory relating to enterprise combination, and published work dealing with the problem of selecting the optimum combination of two enterprises, with the real situation existing on grazing properties carrying both sheep and beef cattle. The second objective was investigated by means or an interview survey of graziers running both sheep and beef cattle in six Western District parishes. A considerable amount of technical information about beef-cattle production in the Western District was collected in the course of the survey, and the more important points are summarised in the thesis. Of particular interest are the findings that very few graziers purchased cattle for fattening purposes, and that beef cattle were relatively more important on large properties than on small properties. It was concluded that static economic theory does not provide an adequate basis for the description of the situation where sheep and cattle graze the same pasture, or for the determination of the optimum allocation of resources between sheep arid beef cattle grazing together. Sheep and cattle graze pasture differently, and therefore different pastures result as the sheep-cattle ratio is altered. In this situation, the postulates on which the iso-resource function is based, that the shared input or inputs should remain homogeneous and constant in quantity as the outputs of the products change, are violated. Thus strictly speaking it is not possible to derive a valid iso-resource function relating the sheep and beef-cattle enterprises with respect to pasture when the sheep and the cattle graze the same pasture. However, if the changes in the pasture are disregarded, it is possible to design experiments to produce practical approximations of iso-resource curves relating sheep and beef cattle. Information obtained from graziers in this and other surveys, and the results of experiments, strongly suggest that for practical purposes it is reasonable to think of an iso-resource curve for sheep and cattle with respect to pasture as being concave towards the origin, that is, the sacrifice rate of sheep for cattle increases as more cattle are added on a sheep property. Farmer estimates and experimental evidence suggests that the marginal sacrifice rate on most properties may be lower than is generally assumed (nutritional standards imply a linear rate of eight merino whethers per 1,000 lb. steer). Almost all the survey graziers believed that the overall relationship between their sheep and their beef cattle with respect to their total feed supply over the whole year was a competitive one. Most estimated that their sheep and their cattle were complementary or supplementary with respect to pasture over a part of the year, including the Spring, and that their sheep and their cattle competed for scarce pasture at some time in the autumn and winter. The survey results showed that the most important reason for the presence of beef cattle on the survey properties was the value of cattle in controlling and utilising pasture and weed growth. However the value 0f cattle for that purpose appeared to decline as the sheep stocking rate increased. It appeared that on many properties the importance of beef cattle in pasture control was a consequence of a desire on the part of the grazier to maximise profits within the restrictions imposed by limitations on sheep numbers including the grazier's desire to limit his personal effort. Beef cattle were also frequently carried for the reason that they provided a means of stabilising income from year to year. Although the survey results tended to confirm previous findings that sheep and beef cattle are supplementary with respect to labour at certain times during the year, and that beef cattle generally require less labour per unit of return than sheep, few graziers said that they carried beef cattle for those reasons. It was concluded that substantial minority of the survey graziers did carry beef cattle partly or solely to satisfy goals other than profit maximisation. The most important of these goals was the minimisation of personal effort, which was shown not by giving labour as a reason for carrying beef cattle, but indirectly in the affirmation of the value of cattle (rather than additional sheep) in pasture control. A few graziers were motivated by a personal preference for beef cattle. In the situation where the available economic theory is inadequate to solve problems of resource allocation between sheep and beef cattle, and where a substantial proportion of graziers carry beef cattle partly or solely for reasons other than profit maximisation, there is little scope for sophisticated economic procedures. Given additional experimental data to provide indicators of probable "substitution rates", it seems that the allocation of resources between sheep and beef cattle on properties such as those in the survey can best be improved by budgeting possible adjustments.
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    Body composition studies in the sheep
    Wardrop, Ian Donald ( 1957)
    When he was Senior Lecturer in Animal Physiology and Production at Melbourne University, Dra T.J. Robinson initiated a series of experiments concerned with the body composition of fat lambs. This study was carried out by the following team of workers under Dr. Robinson's leadership: Mr. Blair-Weste Physiology School; Dr. Binet, Statistics Department; and myself from the school of Agriculture. The aims of this study were to determine: (1) Whether the quality and conformation of a fat lamb carcass could be defined by external body and probe measurements. (2) Whether the antipyrene technique could be used to estimate the total body water in lambs and hence their body composition in terms of total waters fat, and fat free tissue. (3) What relationships might exist between the specific gravity of a lamb carcass and its fat content. (4) Whether sample joints in a lamb carcass were representative of the whole carcass in terms of total bone, muscle, and fate and therefore of total water, fat, and fat free tissue. The first part of the investigation was carried out by Drs. Robinson and ninety and I was in no way involved. The other experiments were carried out jointly by Dr. Robinson, Blair-West and myself. In October, 1953, Dr. Robinson divided 8 newly-born Suffolk cross lambs (all singles) into four similar pairs, and fed each pair on a different plane of nutrition. The lambs, which were made to grow along predetermined growth curves, were weighed fortnightly and antipyrene determinations were carried out monthly. Thus the growth curve of each lamb could be drawn and split up into its component parts - i.e. H2O, fat and fat-free tissue. All lambs were killed when they reached 80 lbs. live weight, and the carcasses deep frozen. When I joined the team, in January, 1955, the carcasses were removed from the cold store and I carried out the specific gravity determinations on them. In order to test the worth of both the antipyrene and specific gravity techniques some standard methods of estimating body composition had to be used as a comparison. It was hoped that the specific gravity of the carcass would give a measure of chemical fat content of the carcass and that antipyrene estimations would give a measure of the total body water in the live sheep. The standard technique used for assessing these estimates was a complete chemical analysis of each lamb into total water, fat protein and residue. One side of each carcass was dissected into total bone, muscle, subcutaneous and intermuscular fat. It was then possible to assess the relationships between the physical and chemical composition of the carcass and the relationships between the physical and chemical composition of sample joints in the carcass and the total carcass. I was responsible for carrying out both the carcass dissections and the chemical analysis. During the course of this work (February, l956), Dr. Robinson took up a new appointment as. Professor of Animal Husbandry at Sydney University. I remained in Melbourne to complete the work under the direction of Dr. D.E. Tribe, the newly appointed Reader in Animal Physiology and Production. The experimental work reported in this thesis is limited to that part of the study for which I was responsible. It will be appreciated therefore, that its full significance lies in its relationship to the work of the other members of the team.
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    Some effects of botanical composition of pasture on the liveweight and wool production of sheep
    Reed, K. F. M (1942-) ( 1972)
    Until recently, the main evidence on which to base pasture mixture. recommendations in Victoria, has been district experience and the results from dry matter ( "mowing") experiments. The grazing experiments described in this thesis, were initiated by Messrs. R. Twentyman, R. Newman, R. Allen and K. Maher of the Department of Agriculture during the period, 1960-196. Their aim was to develop some objective appreciation of the relative value for animal production of some of the sown and unsown species in Western district pastures. In addition to pasture species evaluation, they sought information on the relationship between pasture growth and animal production. Such information is needed so that Agrostologists can better evaluate the many pasture management factors (such as fertilizers, seeding rates, seed. treatments, herbicides, insecticides and defoliation treatments) that affect pasture growth and for which advice is frequently sought.
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    Studies in animal husbandry and agricultural history
    Peel, Lynnette Jean (1938-) ( 1963)
    About 8,000 years ago man began domesticating wild animals and turning their growth and production to his own use. Since this time considerable progress has been made towards the complete utilisation of domesticated animal products but only now is the efficiency of production of these products being investigated. To increase this efficiency a thorough understanding of animal body functions is essential. The importance to the ruminant of one body function - salivation, has not been established although various aspects of this subject have been investigated in recent years . To continue these investigations the development of total salivation in . lambs and the effects of the diversion of saliva on the rumen function in adult sheep were examined. In this second experiment the effects of anaesthesia and lateral recumbency on rumen function were also examined because if the use of these unnatural conditions in some experimental techniques. Some animals have been domesticated but many have not. Nearly 8,000 years have passed since the predecessors of our present day domesticated animals were tamed and conditions have changed considerably. Hence it is feasible that domesticated animals may be less efficient producers of the animal products we now need, than the wild animals. This may be particularly true with regard to protein production in the form of lean meat. To investigate this proposition a body composition study was made on a population of wild kangaroos, and an assessment made of this animal species as a potential producer of lean meat. Not only may the efficiency of agricultural production be increased by re-assessing the livestock potential, but this may also be achieved by re-assessing the agricultural use of any given area of land. In countries settled and developed by people from other countries, the new settlers have applied to the new land the agricultural practices of the old. This has often occurred inspite of vast physical differences between the two countries. The practices have been modified and adapted, the crops and livestock acclimatised, nevertheless the whole range of possible forms of agriculture are usually never investigated. In southern Victoria, for almost a century, vines were grown by European settlers had been familiar with these plants in their own countries. The success and failure of the cultivation of this crop by Europeans in a country very different from their own is examined in the second part of this thesis.
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    The effect of the level of nutrition during pregnancy and lactation on the production of grazing sheep, and the interaction between levels of fertility and nutrition
    Papadopoulos, J. C ( 1956)
    The livelihood of the sheep farmer depends upon the success with which his ewes produce and rear healthy lambs. This is of particular truth in those areas where fat lambs are produced. It is well known that the production of lambs in large number and in good health depends very largely upon the standard of feeding of the ewes during pregnancy and lactation. however in most areas of the world sheep are restricted to those marginal localities in which the agriculturist finds it difficult to produce milk, eggs or vegetables. Under these conditions, the feeding of pregnant and lactating ewes becomes a task of some difficulty. Where food is in short supply it is very necessary to know at what stage of pregnancy or lactation the plane of nutrition should be raised. Thomson and Thomson (1949) have shown that in Scotland the sheep farmer should feed a supplement to his ewes during late pregnancy. Coop (1950) on the other hand has shown that under his New Zealand conditions, the supplement was best reserved until lactation has commenced. It was thought important to know the effect of different planes of nutrition on pregnant and lactating ewes under the conditions of sheep farming in South Victoria. It was for this reason that the present investigation was undertaken. In addition it was thought to be of interest to determine the interaction "if any" between the level of fertility and that of nutrition
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    Oestrogens, isoflavones and the oestrous cycle of the ewe
    Hearnshaw, H ( 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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    Nutritional studies of the young lamb
    Hodge, Russell ( 1967)
    This thesis is based on original research work in a subject approved by the Faculty of Agriculture and is submitted under regulation 3.28 Section 6(a) of the conditions relating to the degree of Master of Agricultural Science. The experiments presented have been published in the Australian Journal of Experimental Agriculture and Animal Husbandry or in the Proceedings of the Australian Society of Animal Production. They were conducted while the author was a member of the Victorian Department of Agriculture which provided the facilities for this work. The first chapter of the thesis is a review of the literature on the digestibility of milk and solid food by the young ruminant - more specifically the calf and the lamb. The second chapter describes two experiments on the apparent digestibility of ewes milk and dried pasture by young lambs and the third chapter comprises two experiments relating to the effect of milk intake on the pasture consumption of lambs. The fourth chapter reports observations on the diet selected by grazing lambs in relation to older sheep. I was responsible for the design of this experiment, was actively associated with the field work and prepared the manuscript for publication. The fifth chapter is a paper on the effect of nutritional restriction during pregnancy on the reproductive performance of crossbred ewes and the subsequent growth of their lambs. The sixth chapter provides summaries of the experiments presented.
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