Peter R. Tozer

A multi-objective programming approach to feed ration balancing and nutrient management

Abstract This paper examines the potential to use multiple objective programming to reduce nutrient excretion from dairy cows through incorporation of nutrient excretion functions into a ration formulation framework. In a typical ration formulation model, a ration is formulated to minimize cost while providing sufficient nutrients to meet the needs of the animal type being fed. To reduce the nutrient loading, rations can be formulated to minimize cost, and nitrogen and phosphorus excretion using multiple objective programming. Rations were initially formulated to minimize cost, nitrogen excretion and phosphorus excretion. Compromise programming was then utilized to examine the impacts on ration formulation of combining the three individual objectives. The multiple objective ration formulation reduced phosphorus excretion by 5% and marginally reduced nitrogen excretion with a small increase in ration cost compared to the single objective minimum cost ration. Multiple objective programming does have the potential to reduce nutrient excretion.

Dust storms – what do they really cost?

Dust storms are frequent in Australia and can have a large impact on the soil resource, the economy and people. There have been few economic studies of the impact of wind erosion worldwide and only one in Australia before this study. While wind erosion impacts on the soil resource at the point of the erosion, the level of economic impact rises as the population and associated infrastructure affected by dust increases. This study estimates the impact on the economy of the state of New South Wales of a single large dust storm called Red Dawn that passed over the eastern coast of Australia on 23 September 2009. Estimates for rural and urban areas are presented with both on- and off-site costs evaluated. The estimated cost is A

Livestock in no-till cropping systems – a story of trade-offs

299 million (with a range of A

Is it economically feasible to harvest by management zone

293–A

Domestic and Trade Impacts of Foot‐And‐Mouth Disease on the Australian Beef Industry

313 million) with most of the cost being associated with household cleaning and associated activities. The dust storm also impacted on many cities on the coast of the state of Queensland, but their costs are not included in this study. This study demonstrates some, but not all, of the major economic costs associated with wind erosion in Australia. Given the annual average cost of dust storms it is suggested that A

Sire selection with multiple objectives

9 million per year would be a conservative estimate of the level of investment required in rural areas for dust mitigation strategies, based on improved land management that could be justified to achieve a positive impact on soil condition and reduce economic losses in rural towns and the more populous coastal cities.

Do Dairy Producers Use Effective Management Practices to Improve the Value of Market Cows?1

The trade-offs of incorporating livestock into no-till cropping systems were examined with respect to ground cover, water balance, nutrient cycling, pest management, whole-farm economics and farmer preferences. The hypothesis that livestock and no-till cropping enterprises may co-exist was investigated using a review of scientific literature and technical reports, information from farmer focus groups and an economic analysis based on case study data from farm consultants. The scientific review focussed on work from Australia, especially western and southern Australia, but also included research related to systems in northern New South Wales and southern Queensland and some related international work. The focus groups and case studies were from the cereal-sheep systems of western and southern Australia. It was concluded that the use of livestock in a no-till system is determined by the productive capacity of the land, the relative profitability of cropping and livestock, the management of herbicide-resistant weeds, sensitivity of soil to damage from grazing and trampling and the farmer’s passion, preference and willingness to apply increased management to livestock. Livestock are an important source of farm diversification and risk management. While net farm income tends to decline as the proportion of livestock increases, variation in net farm income also decreases, reducing volatility in revenue. Livestock need to comprise above 10–15% of net farm income to provide a positive impact on variability of return. Adaptation of mixed-farming systems through rotational grazing, temporary agistment of livestock or removal to non-cropping areas are all management options that may be utilised to remove or reduce potential negative impacts, improve integration and to realise triple-bottom-line gains.

Recursive systems model of fetal birth weight and calving difficulty in beef heifers

The economics of harvesting wheat based on input management zones in the northern wheatbelt of Western Australia was studied using a simulated field of regular dimensions with varying zone sizes and layouts. Fertilizer application rates and crop yield and quality data from field trials of input management were used to estimate the gross crop revenue and harvesting costs from the different field layouts and zone combinations. As a general observation there was no consistency in the results; harvesting by zone generated more gross income in some combinations of field layout and yield quantity scenarios, but not in others. However, there were key factors in determining whether it was profitable to harvest by zone. These were prior knowledge of the potential yield and quality characteristics of grain from each zone in a field, and the layout of zones within a field.

Biotechnology to sustainability: Consumer preferences for food products grown on biodegradable mulches

Although Australia is the sixth largest producer of beef, with production of 2 million metric tonnes, behind regions such as the USA, Brazil and the EU it is the second largest exporter of beef behind Brazil. Average beef exports from Australia are approximately 65% of the total amount of beef produced or about 1.3 million metric tonnes. For these reasons Australia is particularly vulnerable to diseases that are not endemic to the country and could close or disrupt its export markets for beef. In this study we construct a bioeconomic optimization model of the Australian beef industry that captures production and consumption decisions, domestically and internationally, and the impacts on the beef industry of two potentially catastrophic diseases, foot and mouth disease (FMD) and bovine spongiform encephalitis (BSE). The results of the study suggest that depending on control methods losses to the economy of FMD range from

Behavioral, Anatomical, and Physiological Changes in Late Gestation Mares

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