Agriculture and Food Systems - Theses

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    An evaluation of management by objectives as a planning system in a government veterinary service
    Wroth, Robert Harold ( 197-?)
    The need, for field officers, of State Departments of Agriculture to plan their work has been recognized for many years. In the last 10 years particular attention has been paid to program planning by Extension officers. However, it has become apparent that program planning is not being used effectively. Reasons for this range from the lack of defined organizational objectives to difficulties associated with planning at the individual level. The purpose of this study was to test the feasibility of introducing MBO into a Department of Agriculture and its effectiveness in overcoming planning difficulties. In order to test this a MBO system was used to plan for the eradication of bovine Brucellosis by two country regions of the Division of Animal Health in the Victorian Department of Agriculture. Two other regions acted as controls and prepared plans without MBO. The effectiveness of MBO was evaluated on the criteria of involvement and participation of field officers, their job satisfaction, job dissatisfaction, understanding of the plans and the MBO process and the importance of aspects for planning. The major finding was the difference in response of Officers at higher and lower levels of authority and responsibility. Those at higher levels viewed MBO more favourably than those at lower levels, and consequently considered they had significantly more involvement and participation than previously. The study also highlighted deficiencies that existed, such as confusion as to lines of responsibility and lack of two way communication between Regional and Head Office staff, and showed how this can lead to increased job dissatisfaction. The work to be performed was not seen as personally satisfying, thus lowering job satisfaction, and so reduced the apparent success of MBO. However, the overall conclusion was that MBO was a realistic system to use for planning by Department of Agriculture personnel and that it did overcome problems associated with program planning. General and specific recommendations on the use of MBO are made.
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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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    A systems analysis approach to drought reserves in the Hamilton region
    Thatcher, L. P (1944-) ( 1971)
    Following a discussion of drought strategies available to the grazier, one particular strategy, the holding of drought fodder reserves, is examined in detail. The study estimates the least-cost fodder reserves for a range of stocking rate-pasture production regimes in the Hamilton region. The amount of hay feeding required on any stocking-pasture regime is determined from a simulation model of the grazing complex. In this model, three levels of pasture production are stocked at rates ranging from one to ten wethers per acre. The pasture production assumed ranges from "excellent" (i.e. equivalent to the Hamilton Research Station pastures which produce about 10,000 lb. dry matter per annum) to "poor" (35% less). The climatic inputs into the grazing model are the date of Autumn break, for which a formula is derived, and the June to October rainfall. The pasture sub-model is specified and used to derive the pasture which is "grown" in the grazing model. The sheep aspects of the model are reviewed in detail to derive the relationships which are used in the next set of four sub-models in which animal intake is simulated and liveweight changes determined. This set of four sub-models provides for the four situations of animal intake which may be met. These are: The intake of green pasture alone (i.e. all pasture grown after the Autumn Break); the intake of hay alone; the intake of hay and green pasture together; the intake of hay and dry pasture (pasture remaining when the Autumn Break occurs and dry pasture alone which are handled in the same sub-model) The grazing model was validated for the years 1965-67 using data from the Pastoral Research Station, Hamilton, and showed good agreement for all three years simulated, one of which featured a severe drought. Drought feeding requirements (hay) are determined for each of the years 1879 to 1967 and for the ten stocking rate-pasture production regimes, using specific hay feeding rules. These rules, which aim at sheep survival, do not attempt to specify optimum feeding rates per sheep, and any change in them could significantly alter the drought requirements for any of the regimes studied. Furthermore, the estimates are Lased on the assumption that all sheep are fed through the drought. A pre-drought strategy which permitted the sale of certain classes of sheep at some stage during drought would entail lower feed requirements and might have a lower expected cost, especially at high acquisition costs for feed and low replacement costs for sheep. An inventory analysis is then undertaken, based on a 12 month planning period, which utilises the hay feeding probabilities generated in the grazing model, and provides estimates of the least-cost hay reserve. In contrast to previous studies, the price of hay is related to drought length in calculating the penalty cost of inadequate reserves. The effects of varying several parameters of the inventory model are then examined. The parameters varied are hay costs ($4, $10 and $16 per ton), interest rates (7%, 20% and 50%), and salvage values, and these vary in association with the parameters varied in the grazing model (stocking rate, pasture production and the area closed for hay). At the intermediate values for pasture production and hay cost and a 7 per cent per annum interest rate, the minimum-cost reserve rises sharply, from 2 bales per acre at 2 wethers per acre, to 4.5 bales per acre at 3 wethers per acre, 8 bales per acre at 4 wethers per acre, and 15 bales per acre at 5 wethers per acre. The minimum-cost reserve was found to be relatively insensitive to changes in acquisition costs, except at low stocking rates, where a change in reserve of one or two half-bales per sheep was common as acquisition cost varied over the three levels. The effect of interest rates was also examined for the average pasture regime. On the lowest level of hay acquisition cost, ($4 per ton) increasing the rate of interest from 7 to 50 per cent caused reductions of only one half-bale per sheep. However, at high acqusition cost ($16 per ton) raising the interest rate to 20 per cent resulted in a considerable reduction in the minimum-cost reserve, especially on the lower stocking rates, and raising the interest rate to 50 per cent made holding fodder reserves uneconomic for any stocking rate. One measure of the risk in holding various levels of fodder reserve is the standard deviation of the total expected cost. As expected, it was found that this declines as the reserve is expanded to the maximum ever required. However, only a small reduction in standard deviation results from expanding the reserve beyond the minimum-cost level. Finally, estimates were made of the income-maximising stocking rate for each level of pasture production and hay cost, with the wool price at 30, 40 and 50 cents per lb.. At the intermediate values for pasture production (8,000 lb. D.M.) and hay cost ($10 per ton), and with wool at 30 cents per lb. net, the income-maximising stocking rate was 3 wethers per acre. Each increase of 10 cents per lb. in the wool price was generally associated with an increase of one or two wethers per acre in the income-maximising stocking rate. An increase of 2,000 lb. D.M. (from "average" to "excellent") in average annual pasture production was generally associated with an increase of one wether per acre in the income-maximising stocking rate. A reduction of 1,500 lb. from "average" to "poor" pasture. production reduced the income-maximising stocking rate by about one wether per acre. Increasing the hay cost from $4 to $10 per ton reduced the profit-maximising stocking rate by one wether per acre for all combinations of pasture production and wool price examined. However, a further increase in acquisition cost from $10 to $16 per ton only caused a further reduction in the income-maximising stocking rate at the poor level of pasture production: with average pasture production there was little change and with excellent production there was no change in the income-maximising stocking rate.
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    Epidemiological and physiological studies of the effects of peach rosette and decline disease on the peach, prunus persicae L. Batsch
    Smith, P. R ( 1975)
    The incidence in the field of the disease peach rosette and decline (PRD), which is of considerable economic importance in the Goulburn Valley, causing fruit loss and tree death, was shown to increase from 0.9 to 91.3% in an orchard of cv. Golden Queen in 10 years. Similar results were found with the cv. Pullars Cling, in which infection increased from 1.5 to 29.7% over five years. The pattern of spread was mainly from infected trees to contiguous uninfected trees. This is consistent with the view that the main causal agent, prune dwarf virus (PDV), is transmitted only via the transfer of infected pollen : a previous finding in cherries which was confirmed in peaches. Prunus necrotic ringspot virus (PNRV) is the other virus always present in the field in PRD-infected trees. The mode of spread of PNRV is also by pollen. Within the tree, PDV moved erratically from the first infected limb, via phloem but not xylem, into the other limbs well in advance of the appearance of symptoms. Three months after flowering, PDV was detected in 65% of main limbs adjacent to the first infected limbs but in only 30% of limbs more remotely positioned on the tree. However, removing infected limbs within four weeks of flowering, when the initial infection was presumed to have occurred, did not prevent the movement of PDV into the rest of the tree. Laterals from peach trees infected with PRD were tested for the presence of PDV, using woody virus indicators (cvs Golden Queen, Italian Prune and Elberta seedling). Golden Queen was found to be a more reliable indicator for detecting PDV than Italian prune, as the presence of PNRV with PDV killed 71% of the Italian prune buds compared to only 34% of the Golden Queen buds. Golden Queen also developed more obvious foliage symptoms of PDV infection than Elberta seedlings. The probability of failing to detect PDV in infected field trees, using all three indicator plants, was higher in the first year of infection. The rate of spread of PRD was reduced in the orchard by preventing infected trees from flowering, either by removing obviously infected trees or by deblossoming. Removing infected trees resulted in a three-fold reduction in the spread of the disease in two seasons. Removing the flowers from infected trees before pollination reduced the spread of the disease by about half. This, only partial, control of the spread of PRD by tree removal or deblossoming was attributed to the presence of up to 14.3% of trees without symptoms being latently infected with PDV. It was observed that deliberate infection with PDV by pollen also resulted in a slow expression of the symptoms of PRD. The effects of PRD on the growth of young peach trees was obvious in the first three months of growth. There were considerable varietal differences in the severity of this effect. Those varieties based on cvs. Golden Queen or Levis Cling were more severely affected than the variety Elberta. The results from shoot elongation measurements agreed with those obtained from conventional growth analysis methods. These latter experiments showed that, after three months, the dry weight and leaf area of infected Golden Queen plants were reduced by 94%. The fruit yield from mature PRD-free trees was three times that of trees infected for the first season, even though symptoms were apparent only on one limb; and six times that from chronically affected trees infected for two seasons. The effect of virus infection on the photosynthetic ability of single, attached peach leaves was studied under laboratory conditions using infra red gas analysis. The constants derived from the equations describing the relationship between net photosynthesis (Pn) and both irradiance and CO2 concentration were used to analyse the effects of infection by PRD on photosynthetic characteristics of the leaf. The asymptotic value of Pn (Pmax) in young leaves was reduced 15% by PRD-infection, mainly through an increase in the "residual resistance" to 002 diffusion and a decrease of 23% in the parameter indicating photochemical efficiency. There was also evidence that the gas phase resistance was higher in infected leaves at low levels of irradiance. Dark respiration was 51% higher in infected leaves, but this difference was not significant. PRD did not reduce Pn in 60-day-old leaves, normal leaf senescence having a predominant and greater effect. It was concluded that PRD infection had its large effects on growth via a reduction in leaf area; the effects on the photosynthetic capacity per unit leaf area being minor. An effect of PRD infection on the translocation of 14C-assimilatesout of leaves was also observed. Infected leaves retained twice the assimilates than did uninfected leaves. It is concluded that the most promising methods of control of PRD include removal of infected trees, deblossoming suspected infected trees until diagnosis is confirmed, use of virus-tested plants, the gradual destruction of infected orchards and protecting young, healthy orchards from infection either by barrier crops or deblossoming the young plants until they reach an economic bearing age.
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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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    Farm adjustment on the Wimmera plains
    Hunt, C. A. G ( 1971)
    In the past, in some wheat growing areas of Victoria, particularly the Wimmera, there has been almost total reliance on wheat, other enterprises filling a minor role in the farming system. With the introduction of wheat delivery quotas in April 1969, farm operators were faced with a sudden drop in income. The cost-price squeeze has aggravated the income problem. A typical Wimmera Plains wheat farm of 625 acres is small by Australian standards, but it has the potential to produce 7,500 bushels of wheat, or more, under a fertility-maintaining rotation. In 1970-71, however, farms of this size had, on average, a quota of only 4,700 bushels. The possible level of gross income from wheat has been reduced by between $400 and $3,000 per annum, depending on the comparative profitability of alternative enterprises to wheat. The aim of the study was to investigate two important aspects of the farm adjustment problem on the Wimmera Plains; firstly, the best use of resources released from wheat production, and secondly, the potential for adjustment towards optimal resource combinations. A sample of 20 farms, chosen at random from a population of 129, was surveyed in May and June, 1970. The data collected, together with information supplied by the Victorian Department of Agriculture, provided farm planning coefficients. Because of the relatively homogeneous nature of farms with respect to resource complements and enterprise possibilities, the representative farm model approach was considered to be satisfactory for the examination of farm adjustment possibilities on the Wimmera Plains. Using a representative model, linear programming was used to generate profit-maximising farm plans. Variable price programming was used to study the effect of commodity price changes on income. Because of the dominating importance of feed grains in plans, and uncertainty about their prices, enterprise combinations were studied at both "high" and "low" feed-grain prices. To substantiate the results generated for the representative farm model, five of the sample farms were studied individually. When only the "traditional" enterprises (cereals and sheep) were considered, planning results suggested that the five course rotation, pasture, fallow, crop, fallow, crop, with winter-lambing Merino ewes, is the maximum profit plan at both "high" and "low" feed grain prices. Wheat is grown to the level of quota and barley is grown on the remaining cropped area. Income from livestock is minor relative to crop income, providing only 15 to 30 per cent of total gross margin. However, several alternative (or "new') enterprises which are not vet commonly practised in the area were found to offer considerable promise. Oilseed crops, especially oilseed rape, are profitable alternatives to barley, particularly at low feed-grain prices. Even at the current relatively high feed grain prices, and assuming a conservative yield, rapeseed has the potential to lift income from the 625 acre representative farm model by up to $700 per annum. More experience is required with oilseed crops in the area before firm recommendations can be made. Beef cattle, grain feeding of beef, and pigs, can also contribute to increased farm income. Cattle compete directly with sheep for feed, but pigs can be integrated into the existing farming system using farm-grown barley and surplus operator labour. The returns to capital investment in the cattle and pig enterprises were found to be favourable, especially in the case of pigs. If the necessary capital is to be borrowed, however, it is unlikely that there will be surplus disposable income from cattle enterprises during a ten-year repayment period. Gains to the individual farmer from wheat quota negotiability were investigated. The five case-study farms were considered as a "mini-market" for wheat quota under perfect competition. Assuming that the five operators bought or sold quota in order to maximise their income, the average theoretical gain per farm, from negotiability, was between $100 and $200 per annum, depending on the price of barley. In the theoretical quota market seven thousand bushels of wheat quota were exchanged between the five farms. The return to labour and management which is possible on the typical 625 acre Wimmera Plains farm was found to be below an "acceptable" level of $3,500 per annum. However, at current land values, which have fallen substantially since 1968, the purchase or lease of additional land by typical farmers seems to be profitable. Results indicated that the machinery and labour capacity of the "typical" 625 acre property was sufficient to effectively farm more than 1,000 acres. Eleven per cent of the 129 farms in the Wimmera study area were found to be smaller than 500 acres in size. For such farms, additional land as well as additional quota would probably be necessary for viability, at least at low feed-grain prices.
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    The phosphorus requirements of wheat crops grown in the Victorian Mallee
    McClelland, V. F ( 1969)
    Some of the material presented in this thesis is based on papers which are already published or are in the process of publication. Paper 1 is taken from - McClelland, V. P. (1968). - Superphosphate on wheat : The cumulative effect of repeated applications on yield response. Aust. J. agric. Res. 19, 1-8. and paper 2 from - McClelland, V. P. (1968). - Superphosphate on wheat z The influence of previous level of application on current effect. Aust. J. exp. Agric. Anim. Husb. 9, 622-4. Other publications from this thesis will also be in this author's name.