School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemSpecies composition of improved dairy pastures in Bumthang, Bhutan( 2005)Multilocation studies of forage mixtures since 1970s identified white clover, cocksfoot, tall fescue and Italian ryegrass as appropriate pasture mixture for Bhutanese temperate environments. To date, there has been limited evidence on the long-term sustainability of these mixtures in farmer managed environments. Forty-one grazed pastures and fifty cut pastures were sampled in the elevation range of 2500-3500 m asl. Species composition was expressed in terms of tiller/growing point density of grass and legume species. Tiller core technique was used to measure plant densities. Soil samples were collected from depth profile of 5- 15cm. The dried soil samples were analysed for P, K, pH and texture. Dairy farmers were interviewed to obtain paddock histories and information on defoliation management. The tiller density of cocksfoot was higher in cut pastures though cocksfoot was negatively associated with cutting frequency. Cocksfoot was negatively associated with white clover and Italian ryegrass for both cut and grazed pastures. Soil pH was negatively associated with pasture age. Negative associations between K and pasture age was observed for both cut and grazed pastures. White clover was positively associated with P in grazed pastures. Italian ryegrass was positively associated with P, soil pH and moisture in grazed pastures. Available P was negatively associated with elevation. Cocksfoot abundance in cut pastures has been attributed to cocksfoot being a well adapted hay type species. The lower tiller density of cocksfoot in grazed pastures may be the consequence of continuous grazing without adequate rest period. White clover is positively associated with available P due to white clover being a well known plant that requires adequate levels of available P. The positive association between Italian ryegrass and pH has been explained by the greater availability of P with increasing pH. A decline in the levels of available K in older pastures was related to repeated defoliation without K inputs to replace the losses.
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ItemThe effect on some milking characteristics of cows of changing the flow rate thresholds of automatic cluster removers in a seasonally calving dairy herd( 2004)An experiment to investigate the effects of altering the end-of-milking point values of automatic cluster removers (ACRs) from 0.40 kg/min (Control) to 0.70 kg/min (Fixed ACR), or 1.00 kg/min (Rising ACR) over an extended period from the peak until the end of lactation of a seasonally calving pasture based herd has been conducted at the Victorian Department of Primary Industries Ellinbank research dairy. One hundred and ninety two cows. and heifers were used in the experiment (64 animals statistically allocated to each treatment group). A comparative analysis of results for each treatment group is presented for average milk yield, average milking duration, average maximum milking duration, average milk flow rate, average peak milk flow rate and udder health. The Fixed ACR treatment reduced the average daily milking duration by up to 7.6%, but only for a small portion of the treatment period. The Rising ACR treatment reduced the average daily milking duration significantly by up to 15.3%, for the majority of the treatment period. The Fixed ACR treatment did not reduce the average daily maximum milking duration whilst the Rising ACR treatment reduced the average daily maximum milking duration significantly by up to 17.9%, for the more than half of the treatment period. A marginal increase in average milk flow rate was observed for the Rising ACR treatment. Even though the Rising ACR treatment began the experiment with higher average peak flow rate for AM and PM it declined less than the Fixed. ACR or Control treatment throughout lactation, providing a mechanism for the, removal of the same amount of milk in a reduced time when compared with the other treatments. However the difference observed in peak flow rates was not statistically significant. No difference was found amongst the treatment groups when analysed for new cases of sub-clinical or clinical mastitis. The geometric mean of individual cow cell counts was significantly reduced for the Rising ACR treatment in the latter stages of lactation. Flow rate curves have been constructed from real milking data and are presented as examples of the large variation of actual- flow rate from a cows udder. The flow rates curves are used to track individual cows through lactation to observe changes in the cow's milking characteristics. Theoretical consideration is given to how particular types, or brands, of ACR operate under various conditions and it is shown that the results from this experiment could be replicated by using other types of ACR if they are managed correctly. This study has shown that significant labour productivity. benefits could be achieved by, increasing the ACR end-of-milking point settings to 1.00 kg/min without impacting milk yield. However, further work is suggested to ensure that udder health is not compromised. This is to certify that the thesis comprises only my original work except here indicated in the preface; due acknowledgement has been made in the text to all other material used; the thesis is 19400 words in length, inclusive of footnotes, but exclusive of tables, maps, appendices and bibliography.
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ItemA farm management economic analysis of future dairy systems in the Goulburn Valley( 2002)Case studies were used to analyse the organisation and management of two irrigated dairy farm businesses. In particular, the focus was to . identify the economic' aspects of current and future farming systems in the Goulburn Valley. The approach involved focusing on farmers, the farm business, and the specific details of the farm system that farmers were managing. A whole-farm perspective was relevant as it provided details of the farm system and farmer characteristics that substantially influence how they respond to market changes. The economic 'analyses revealed that theoretical concepts often match the practical management of irrigated. dairy businesses. Also, relatively simple farm management budgets, which capture the full effect on management of the whole farm system from development, have a useful role in providing farmers with effective information about the medium-term growth opportunities on irrigated dairy farms in the Goulburn Valley. From these results it can be concluded that 'it is not what you do, but how you do it' that primarily determines the level of success in achieving goals.
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ItemA process for practice : learning for change in the dairy industry( 2002)The dairy industry in Victoria, and indeed agriculture more generally, is facing a new generation of increasingly complex issues. Problems associated with issues such as the deregulation of markets and sustainable farming practices are ones which seemingly can not be addressed through the application of technology alone. In 1999 a review of human resource development and extension (HRD&E) in Australia's dairy industry identified that for farmers to be adequately supported in tackling such issues, the HRD&E system required extensive development, particularly in the area of understanding farmer learning. Learning plans were discussed as a possible means by which this could be achieved, however there was much ambiguity associated with this term, particularly for extension practitioners. Thus this project was born and aimed to explore the learning, motivation and change behaviour of dairy farmers in south west Victoria in relation to improving grazing management performance. After a review of the potential paradigms through which this research could be explored, practice theory and the interplay model were found to be the most appropriate, as such an approach enabled the researcher to engage farmers at the level of on farm practice. The underlying epistemological paradigm through which the area of learning plans was explored combined the constructivist and critical theory positions, while the methodologies applied were a collective case study approach, using a Straussian style of grounded theory. Through the interplay model it became clear that for this research to be effective, an improved understanding of farmer learning needed to be examined in terms of the provision of extension services. As such, new theory generated was explored and applied in practice using an action research approach, engaging five extension practitioners from around the state of Victoria. Overall, this research has produced a new model which describes farmer learning as a process of change where action and intention are informed, challenged and balanced by potentially opposing worldviews. The action research phase of the project identified that such learning would be best facilitated through partnerships with extension. Such partnerships involve the practice of extension working towards better understanding the farmers needs as well as the nature of their farming system, and then using this understanding to inform the application of extension resources. The process through which this concept was generated is clearly outlined and discussed, as are the implications that this research presents for the future development of extension in Victoria.
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ItemLearning from the group : a case study of the focus farm project in Gippsland, Victoria( 2001)This thesis examines the dairy industry 'focus farm project, in Gippsland, Victoria. This study evaluates the effectiveness of the focus farm project as an extension-learning program at the three farmer levels - the focus farm family, the support group and the wider local dairying community. It explores the process of the project, including the communication tools, the facilitated group approach and seeks evidence of the decision-making process. The focus farm project intends to improve on farm production efficiency through improved decision-making processes. It utilises consultant led, facilitated farmer groups. The three focus farms in this study include Labertouche, Nambrok and Yarram districts. The farmer groups are exclusive, and the wider community has access to the program by invitation to farm open days twice a year and through monthly industry newsletters. Qualitative and quantitative research methods were used to assess the focus farm project, including participant observation, semi-structured and structured interviews and thematic document analysis. A participatory action research (PAR) approach was undertaken to identify the applicability of farmer self-evaluation in future projects. This model was referred to as the 'second generation contact model'. It suggests the possibility of creating a bridge between support group members and the wider dairying community that both can use to verify and legitimate project inputs and outcomes. The findings showed that the understanding of the project aims and objectives were varied among the three farmer levels in comparison with the original intentions reported in the policy documents. The principle aim of the project, improving the decision making process, was not well articulated among focus farm groups. This is attributable in part to a lack of planning and focus at all levels on making the decision-making process transparent. The project model has the potential to integrate complexity and sustainable management practices into the focus farm discourse. There is evidence that farmers are interested in integrating approaches. The 'facilitated group approach' was not effectively demonstrated in the current project model. Instead, the findings indicate the project followed a personalised consultant model. The groups' identity was also influential in the project outcomes and activities. Similarly, participation of the wider community was affected by the group identity. Finally, the PAR approach provided a unique experience for core group members to contact the local dairying community and identify their opinions of project benefits. The results of the interviews has led to the conceptualisation of the 'second generation model', that is, farmer participants self-evaluating their core group management as well as supporting the focus farm family; and taking responsibility to disseminate focus farm decisions and activities outside the immediate group. In this way they may be understood as extension activists within the wider community. It is anticipated that this aspect of the model may be useful to future group extension activities planned within the dairy and other commodity industries.
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ItemWater-use efficiency and profitability on irrigated dairy farms in northern Victoria and southern New South Wales( 2001)Three studies were conducted to look at water use efficiency (WUE) and profitability on irrigated dairy farms in northern Victoria and southern New South Wales. The studies consisted of (i) a large survey of WUE on dairy farms, (ii) monitoring WUE on 20 farms over five seasons, and (iii) an economic evaluation of various development options for a case study farm. The factors associated with high WUE, and the potential for farms to improve WUE, were examined in the first two studies. The third study evaluated options for the case study farm that could result in higher WUE, increased profit, and meet the farm owners objectives. Water use efficiency was defined as the amount of milk (kg milk fat plus protein) produced from pasture per megalitre of water (irrigation plus effective rainfall). The survey of 170 randomly selected, irrigated, dairy farms in northern Victoria and nine in southern New South Wales found there was a large range in WUE (25 to 115 kg milk fat plus protein/MI), which indicated potential for many farms to substantially improve WUE. The high WUE farms, when compared with the low group, had higher estimated pasture consumption per ha and per ML, higher stocking rates, used higher rates of nitrogen fertiliser, had higher milk production per cow, and directed a higher proportion of energy consumed into milk production. The survey data also confirmed that irrigated dairy farm systems are complex and variable. Increases in WUE of over 15 kg milk fat + protein/ML were achieved on eight of the monitor farms over the last five years. However, an investment in improving WUE is often complex and is likely to impact on a number of areas of the farm business. For example, increasing WUE by increasing pasture utilisation may require an increase in stocking rate and herd size. An increase in herd size may make it necessary to replace some of the existing infrastructure, such as, the dairy, or employ more labour. The case study farm data indicates that in the past four seasons there was no simple, direct association between WUE and profitability. Economic analysis of some development options for the case study farm found that there were some options that were compatible with the objectives of the farm owners and were likely to result in both increased WUE, and increased profit. Efficient use of irrigation water is one of many factors that contribute to whole farm profit. Therefore, development options that have the potential to increase WUE also have potential to increase whole farm profit, and thus the development options investigated for irrigated dairy farms should always include options that have the potential to increase WUE. The approach of conducting an industry survey to identify areas of farm management where there may be potential to improve, and then looking at production and economic efficiency in past years on individual case study farms, provided a good base for evaluating development options and making farm management decisions. However, survey data and data from previous seasons appeared to be of limited value to farm managers unless they are used as a base to do some economic analysis of options for the future.