Information on the nutritive value and in vitro fermentation characteristics of native shrubs in ... more Information on the nutritive value and in vitro fermentation characteristics of native shrubs in New Zealand is scant. This is despite their potential as alternatives to exotic trees and shrubs for sup-plementary fodder, and mitigation of greenhouse gas and soil erosion on hill country sheep and beef farms. The objectives of this study were to measure the in vitro fermentation gas production, predict parameters of in vitro fermentation kinetics and to estimate in vitro fermentation of volatile fatty acids (VFA), microbial biomass (MBM) and greenhouse gases of four native shrubs (Coprosma robusta, Griselinia littoralis, Hoheria populnea and Pittosporum crassifolium) and an exotic fodder tree species, Salix schwerinii. Total in vitro gas production was higher (p<0.05) for natives than S. schwerinii. Prediction using the single pool model resulted in biologically incorrect negative in vitro total gas production from the immediately soluble fraction of the native shrubs. However, the...
This session covers twenty six papers from different authors 2006 Seasonal Outlook, David Stephen... more This session covers twenty six papers from different authors 2006 Seasonal Outlook, David Stephens and Michael Meuleners, Department of Agriculture 2006 Wheat Market Outlook, Tony Smith, Plum Grove Commodity Trading Solutions Will Budgets Change in 2006? Peter Tozer, Department of Agriculture Wheat varieties – what does the industry need and how do we get closer? David Bowran Department of Agriculture Performance of Wheat Varieties in National Variety Testing (NVT) WA, Peter Burges, Agritech Crop Research Survey of lupin root health (in major production areas), Geoff Thomas, Bill MacLeod, Ken Adcock, Katie Bell, Ciara Beard and Anne Smith, Department of Agriculture Managing root disease under intensive cropping, Bill MacLeod, and Vivien Vanstone, Department of Agriculture Investigation into the adequacy OF SEALED FARM SILOS IN Western Australia to control phosphine-resistant Rhyzopertha dominica, C.R. Newman, Department of Agriculture Phosure – Extending the Life of Phosphine, Gabrielle Coupland and Ern Kostos, Cooperative Bulk Handling IWM performs over 5 years in 33 focus paddocks, Peter Newman and Glenn Adam, Department of Agriculture Maintaining wheat and lupin yields using phase pastures and shielded sprayers to manage increasing herbicide resistance, Caroline Peek, Nadine Eva, Chris Carter and Megan Abrahams, Department of Agriculture Can sheep selectively graze weeds out of crops? A model for using sheep rather than chemicals, Tim Wiley, Department of Agriculture and Dean Revell, CSIRO Livestock Environmental Protection (Clearing of Native Vegetation) Regulations 2004, Anne Finlay, Department of Environment What lies beneath? – Understanding constraints to productivity below the soil surface, Stephen Davies and Chris Gazey, Department of Agriculture, Bob Gilkes, Dan Evans and Tania Liaghati, University of Western Australia Phoma blight (P. schneiderae), a risk for WA lupins? Geoff Thomas and Mark Sweetingham, Department of Agriculture The 2005 Wheat streak mosaic virus epidemic in New South Wales and the threat posed to the Western Australian wheat industry, Roger Jones and Nichole Burges, Department of Agriculture Zone Management for fun and Profit, Department of Agriculture, Tony Rosser and Owen Mann, Great Northern Rural Annual Ryegrass Toxicity (ARGT) – How to manage the Risk, Marnie Thomas, Department of Agriculture The future of lupin varieties, Wayne Parker, Department of Agriculture Analysis of a wheat-pasture rotation in the 330mm annual rainfall zone using the STEP model, Andrew Blake and Caroline Peek, Department of Agriculture Value Added Opportunities for Lupins in High Value Feed and Food Markets, Jason Craig and Mark Tucek, Cooperative Bulk Handling An overview of the potential for a Biofuels Industry in Western Australia, Anne Wilkins and Nathan Hancock, Department of Agriculture The GMO Picture – a Reality Check, Dr Sue Sutherland, Department of Agriculture Nitrogen applied in splits rather than all applied at seeding returns higher gross income from wheat cropped on a leaching sandy soil at Muresk (Central agricultural region), Darshan Sharma, Department of Agriculture and Lionel Martin, Muresk Institute, Curtin University of Technology Potassium response in cereal cropping within the medium rainfall central wheatbelt, Jeff Russell, Department of Agriculture, Angie Roe and James Eyres Farm Focus consultants Western Region Barley Variety Guide2006, Alaina Smith, Blakely Paynter and Andrea Hills, Department of Agricultur
We provide empirical evidence to decompose productivity growth of a group of producers into techn... more We provide empirical evidence to decompose productivity growth of a group of producers into technical change and efficiency measures at the farm level. Using four years of farm-level data from forty-five grain producers in the low- to medium-rainfall zone of Western Australia, we decompose productivity numbers to analyze total factor productivity. The results show that producers are generally technical, mix, and scale efficient, but the results for input and output mix efficiencies vary. The outcomes for input mix efficiency suggest that producers face some rigidity in their production decisions. In contrast, output mix efficiency suggests that most producers adjust their output mixes to account for different seasonal conditions and enterprise mixes.
Seven different remaining value functions for tractors and harvesters were estimated using data f... more Seven different remaining value functions for tractors and harvesters were estimated using data from advertised prices for used farm equipment. The generalised Box-Cox model was used to nest six of the seven functions. The more complex Box- Cox function explained the data better, but simpler models such as the sum-of-theyears- digits, or double-square root models were no different and were easier to manipulate to estimate depreciation rates and costs. There were up to three components of depreciation, drive-away, age and use related, depending on functional form. Drive-away depreciation is the immediate loss in value of a machine due to purchase, in some models this depreciation was higher than either age or use related depreciation. When drive-away depreciation was treated as a separate cost or when there was no drive-away depreciation, due to functional form, age and use depreciation costs were approximately equal.
Previous bioeconomic studies have mainly concentrated on beef operations, principally stocker act... more Previous bioeconomic studies have mainly concentrated on beef operations, principally stocker activities, and rangeland conditions. These studies have assumed that the rancher determines some desired weight gain per head over a period, usually one year, and this weight gain is achieved by utilizing a resource such as pasture or grazing rangeland. This study differs to the previous research as we are interested in the interactions between pasture productivity and milk yield in an intensive grazing situation, rather than extensive grazing and incorporate more than one type of pasture or forage type into a model of a dairy system. We develop a discrete optimal control model based on the energy demand of a herd of dairy cows and the supply of energy available from the various forages produced on a model dairy farm. The objective of the model is to maximize the net present value of the flow of profits generated by the dairy. Incorporated into the model is a herd dynamics sub-model, a tra...
A set of simulations were run to estimate the impact on gross margins due to improvements in catt... more A set of simulations were run to estimate the impact on gross margins due to improvements in cattle breeding efficiency and other management factors in extensive pastoral systems in Western Australia. The output from the simulations was integrated into a statistical model of gross margin as a function of breeding and management variables. The simulations showed that gross margin was an increasing function of breeding rates, but age at first breeding and age at sale of offspring had variable effects on the gross margin of the enterprise. The statistical model illustrated that for a one per cent increase in breeding rates, an increase in gross income of $5274 was possible. The optimal ages at first breeding and sale of offspring were 20.6 months and 10.8 months respectively. Information generated by the simulation and the statistical model allows management to identify the breakeven value, or limit of expenditure, of changes to the system, beyond which the change will not increase ent...
Cassey, Andrew J., Jeremy Sage, and Peter Tozer (2015). "Assessing the Impact of Labor Short... more Cassey, Andrew J., Jeremy Sage, and Peter Tozer (2015). "Assessing the Impact of Labor Shortages as a Marketing Barrier." Unpublished manuscript, Washington State University.
LambMax WA was a tightly integrated program based on collaboration between innovative farmers wit... more LambMax WA was a tightly integrated program based on collaboration between innovative farmers with an interest in sheep production, the Department of Agriculture Western Australia and the Animal Biology group at The University of Western Australia. The basic aim of the activity was to demonstrate the potential management strategies to increase weaning percentages in ewe flocks on farms in Western Australia (1). On-farm studies were conducted to investigate the individual components contributing to the overall ewe lambing performances on five farms in 2003 and 2004 with issues learnt during the first year being used to improve the trials in 2004. This paper reports the results of an economic assessment of the strategies examined in the LambMax activity. AIM To conduct an economic assessment of the management strategies applied to ewe flocks in the LambMax trials. METHOD The data collected from the trials were incorporated into a gross margin (GM) model that represented and compared t...
The New Zealand dairy industry produces approximately 2 million surplus calves annually. These un... more The New Zealand dairy industry produces approximately 2 million surplus calves annually. These under-utilised animals have a potential value that is estimated to exceed NZD$1 billion per annum. Growing surplus dairy calves in an accelerated beef enterprise for slaughter prior to one year of age is being investigated for potential positive financial implications. This study quantifies the physical and financial performance of Hereford x Friesian-Jersey steers (slaughtered at less than one year of age), compared to traditional bull-beef production. The steers achieved slaughter live-weights of 251, 303 and 349 kg/head at 8, 10 and 12 months of age respectively (118, 146 and 175 kg/head carcass weight). The meat schedule price required for the proposed enterprise to break even with traditional 24-month bull-beef was $6.84, $6.55 and $5.99/kg for steers slaughtered at 8, 10 and 12 months of age respectively.
New Zealand hill country sheep and beef farms contain land of various slope classes. The steepest... more New Zealand hill country sheep and beef farms contain land of various slope classes. The steepest slopes have the lowest pasture productivity and livestock carrying capacity and are the most vulnerable to soil mass movements. A potential management option for these areas of a farm is the planting of native shrubs which are browsable and provide erosion control, biodiversity, and a source of carbon credits. A bioeconomic whole farm model was developed by adding a native shrub sub-model to an existing hill country sheep and beef enterprise model to assess the impacts on feed supply, flock dynamics, and farm economics of converting 10% (56.4 hectares) of the entire farm, focusing on the steep slope areas, to native shrubs over a 50-year period. Two native shrub planting rates of 10% and 20% per year of the allocated area were compared to the status quo of no (0%) native shrub plantings. Mean annual feed supply dropped by 6.6% and 7.1% causing a reduction in flock size by 10.9% and 11.6...
Hoggets (ewe lambs aged 4 to 16 months) can be bred from approximately 8 months of age for potent... more Hoggets (ewe lambs aged 4 to 16 months) can be bred from approximately 8 months of age for potentially increased flock production and profit, however most New Zealand hoggets are not presented for breeding and their reproductive success is highly variable. Bio-economic modelling was used to analyse flock productivity and profit in four sets of scenarios for ewe flocks with varying mature ewe (FWR) and hogget (HWR) weaning rate combinations. Firstly, hogget breeding was identified to become profitable when break-even HWRs of 26% and 28% were achieved for flocks with FWRs of 135% and 150%, respectively. Secondly, relatively smaller improvements in FWR were identified to increase profit to the same level as larger improvements in HWR. Thirdly, a high performing flock with FWR and HWR both ≥ the 90th percentile currently achieved commercially, was the most profitable flock modelled. Fourthly, a FWR was identified with which a farmer not wishing to breed hoggets could have the same profi...
Breeding hoggets (ewe lambs aged four to 16 months) at 8 to 9 months of age has a number of poten... more Breeding hoggets (ewe lambs aged four to 16 months) at 8 to 9 months of age has a number of potential benefits, including increased lamb production and profitability. However, the majority of hoggets in New Zealand are not bred due to producer concerns regarding their variable reproductive success and increased feed demand. Simulation modelling was used to quantify effects of hogget breeding on sheep numbers, lamb production, sheep feed demand, and sheep enterprise cash operating surplus (COS) compared with a flock not breeding hoggets. Hogget weaning rate (HWR) was modelled at 0%, 60%, 80%, and 100% and combined with mature ewe flock weaning rates (FWR) of 132% and 150%, while maintaining total annual sheep feed demand. For each FWR, increased HWR reduced total sheep numbers, increased the proportion of sheep feed demand for lamb production, increased total numbers of lambs weaned, and increased COS. Therefore, achieving even a relatively low HWR of 60% can improve sheep enterprise...
Considering the current low prices for coarse wool (fibre diameter > 30 µm), a grading up tran... more Considering the current low prices for coarse wool (fibre diameter > 30 µm), a grading up transition to a shedding flock may eliminate wool harvesting costs and increase sheep farm profit. This transition could be achieved by breeding non-shedding ewes with Wiltshire rams. A bio-economic system-dynamics model of a pastoral sheep farming enterprise was used to simulate this grading up transition from 2580 Romney ewes to a similarly-sized flock of fully shedding third or fourth cross Wiltshire–Romney ewes. The total annual sheep feed demand was constrained within a ±5% range to minimise disruption to the on-farm beef cattle enterprise. Wool harvesting expenses were eliminated after seven years of transition, and with reduced feed demand for wool growth, the post-transition shedding flocks had more ewes producing more lambs and achieving greater annual profit compared with the base Romney flock. The net present values of transition were 7% higher than the maintenance of the base Rom...
Information on the nutritive value and in vitro fermentation characteristics of native shrubs in ... more Information on the nutritive value and in vitro fermentation characteristics of native shrubs in New Zealand is scant. This is despite their potential as alternatives to exotic trees and shrubs for sup-plementary fodder, and mitigation of greenhouse gas and soil erosion on hill country sheep and beef farms. The objectives of this study were to measure the in vitro fermentation gas production, predict parameters of in vitro fermentation kinetics and to estimate in vitro fermentation of volatile fatty acids (VFA), microbial biomass (MBM) and greenhouse gases of four native shrubs (Coprosma robusta, Griselinia littoralis, Hoheria populnea and Pittosporum crassifolium) and an exotic fodder tree species, Salix schwerinii. Total in vitro gas production was higher (p<0.05) for natives than S. schwerinii. Prediction using the single pool model resulted in biologically incorrect negative in vitro total gas production from the immediately soluble fraction of the native shrubs. However, the...
This session covers twenty six papers from different authors 2006 Seasonal Outlook, David Stephen... more This session covers twenty six papers from different authors 2006 Seasonal Outlook, David Stephens and Michael Meuleners, Department of Agriculture 2006 Wheat Market Outlook, Tony Smith, Plum Grove Commodity Trading Solutions Will Budgets Change in 2006? Peter Tozer, Department of Agriculture Wheat varieties – what does the industry need and how do we get closer? David Bowran Department of Agriculture Performance of Wheat Varieties in National Variety Testing (NVT) WA, Peter Burges, Agritech Crop Research Survey of lupin root health (in major production areas), Geoff Thomas, Bill MacLeod, Ken Adcock, Katie Bell, Ciara Beard and Anne Smith, Department of Agriculture Managing root disease under intensive cropping, Bill MacLeod, and Vivien Vanstone, Department of Agriculture Investigation into the adequacy OF SEALED FARM SILOS IN Western Australia to control phosphine-resistant Rhyzopertha dominica, C.R. Newman, Department of Agriculture Phosure – Extending the Life of Phosphine, Gabrielle Coupland and Ern Kostos, Cooperative Bulk Handling IWM performs over 5 years in 33 focus paddocks, Peter Newman and Glenn Adam, Department of Agriculture Maintaining wheat and lupin yields using phase pastures and shielded sprayers to manage increasing herbicide resistance, Caroline Peek, Nadine Eva, Chris Carter and Megan Abrahams, Department of Agriculture Can sheep selectively graze weeds out of crops? A model for using sheep rather than chemicals, Tim Wiley, Department of Agriculture and Dean Revell, CSIRO Livestock Environmental Protection (Clearing of Native Vegetation) Regulations 2004, Anne Finlay, Department of Environment What lies beneath? – Understanding constraints to productivity below the soil surface, Stephen Davies and Chris Gazey, Department of Agriculture, Bob Gilkes, Dan Evans and Tania Liaghati, University of Western Australia Phoma blight (P. schneiderae), a risk for WA lupins? Geoff Thomas and Mark Sweetingham, Department of Agriculture The 2005 Wheat streak mosaic virus epidemic in New South Wales and the threat posed to the Western Australian wheat industry, Roger Jones and Nichole Burges, Department of Agriculture Zone Management for fun and Profit, Department of Agriculture, Tony Rosser and Owen Mann, Great Northern Rural Annual Ryegrass Toxicity (ARGT) – How to manage the Risk, Marnie Thomas, Department of Agriculture The future of lupin varieties, Wayne Parker, Department of Agriculture Analysis of a wheat-pasture rotation in the 330mm annual rainfall zone using the STEP model, Andrew Blake and Caroline Peek, Department of Agriculture Value Added Opportunities for Lupins in High Value Feed and Food Markets, Jason Craig and Mark Tucek, Cooperative Bulk Handling An overview of the potential for a Biofuels Industry in Western Australia, Anne Wilkins and Nathan Hancock, Department of Agriculture The GMO Picture – a Reality Check, Dr Sue Sutherland, Department of Agriculture Nitrogen applied in splits rather than all applied at seeding returns higher gross income from wheat cropped on a leaching sandy soil at Muresk (Central agricultural region), Darshan Sharma, Department of Agriculture and Lionel Martin, Muresk Institute, Curtin University of Technology Potassium response in cereal cropping within the medium rainfall central wheatbelt, Jeff Russell, Department of Agriculture, Angie Roe and James Eyres Farm Focus consultants Western Region Barley Variety Guide2006, Alaina Smith, Blakely Paynter and Andrea Hills, Department of Agricultur
We provide empirical evidence to decompose productivity growth of a group of producers into techn... more We provide empirical evidence to decompose productivity growth of a group of producers into technical change and efficiency measures at the farm level. Using four years of farm-level data from forty-five grain producers in the low- to medium-rainfall zone of Western Australia, we decompose productivity numbers to analyze total factor productivity. The results show that producers are generally technical, mix, and scale efficient, but the results for input and output mix efficiencies vary. The outcomes for input mix efficiency suggest that producers face some rigidity in their production decisions. In contrast, output mix efficiency suggests that most producers adjust their output mixes to account for different seasonal conditions and enterprise mixes.
Seven different remaining value functions for tractors and harvesters were estimated using data f... more Seven different remaining value functions for tractors and harvesters were estimated using data from advertised prices for used farm equipment. The generalised Box-Cox model was used to nest six of the seven functions. The more complex Box- Cox function explained the data better, but simpler models such as the sum-of-theyears- digits, or double-square root models were no different and were easier to manipulate to estimate depreciation rates and costs. There were up to three components of depreciation, drive-away, age and use related, depending on functional form. Drive-away depreciation is the immediate loss in value of a machine due to purchase, in some models this depreciation was higher than either age or use related depreciation. When drive-away depreciation was treated as a separate cost or when there was no drive-away depreciation, due to functional form, age and use depreciation costs were approximately equal.
Previous bioeconomic studies have mainly concentrated on beef operations, principally stocker act... more Previous bioeconomic studies have mainly concentrated on beef operations, principally stocker activities, and rangeland conditions. These studies have assumed that the rancher determines some desired weight gain per head over a period, usually one year, and this weight gain is achieved by utilizing a resource such as pasture or grazing rangeland. This study differs to the previous research as we are interested in the interactions between pasture productivity and milk yield in an intensive grazing situation, rather than extensive grazing and incorporate more than one type of pasture or forage type into a model of a dairy system. We develop a discrete optimal control model based on the energy demand of a herd of dairy cows and the supply of energy available from the various forages produced on a model dairy farm. The objective of the model is to maximize the net present value of the flow of profits generated by the dairy. Incorporated into the model is a herd dynamics sub-model, a tra...
A set of simulations were run to estimate the impact on gross margins due to improvements in catt... more A set of simulations were run to estimate the impact on gross margins due to improvements in cattle breeding efficiency and other management factors in extensive pastoral systems in Western Australia. The output from the simulations was integrated into a statistical model of gross margin as a function of breeding and management variables. The simulations showed that gross margin was an increasing function of breeding rates, but age at first breeding and age at sale of offspring had variable effects on the gross margin of the enterprise. The statistical model illustrated that for a one per cent increase in breeding rates, an increase in gross income of $5274 was possible. The optimal ages at first breeding and sale of offspring were 20.6 months and 10.8 months respectively. Information generated by the simulation and the statistical model allows management to identify the breakeven value, or limit of expenditure, of changes to the system, beyond which the change will not increase ent...
Cassey, Andrew J., Jeremy Sage, and Peter Tozer (2015). "Assessing the Impact of Labor Short... more Cassey, Andrew J., Jeremy Sage, and Peter Tozer (2015). "Assessing the Impact of Labor Shortages as a Marketing Barrier." Unpublished manuscript, Washington State University.
LambMax WA was a tightly integrated program based on collaboration between innovative farmers wit... more LambMax WA was a tightly integrated program based on collaboration between innovative farmers with an interest in sheep production, the Department of Agriculture Western Australia and the Animal Biology group at The University of Western Australia. The basic aim of the activity was to demonstrate the potential management strategies to increase weaning percentages in ewe flocks on farms in Western Australia (1). On-farm studies were conducted to investigate the individual components contributing to the overall ewe lambing performances on five farms in 2003 and 2004 with issues learnt during the first year being used to improve the trials in 2004. This paper reports the results of an economic assessment of the strategies examined in the LambMax activity. AIM To conduct an economic assessment of the management strategies applied to ewe flocks in the LambMax trials. METHOD The data collected from the trials were incorporated into a gross margin (GM) model that represented and compared t...
The New Zealand dairy industry produces approximately 2 million surplus calves annually. These un... more The New Zealand dairy industry produces approximately 2 million surplus calves annually. These under-utilised animals have a potential value that is estimated to exceed NZD$1 billion per annum. Growing surplus dairy calves in an accelerated beef enterprise for slaughter prior to one year of age is being investigated for potential positive financial implications. This study quantifies the physical and financial performance of Hereford x Friesian-Jersey steers (slaughtered at less than one year of age), compared to traditional bull-beef production. The steers achieved slaughter live-weights of 251, 303 and 349 kg/head at 8, 10 and 12 months of age respectively (118, 146 and 175 kg/head carcass weight). The meat schedule price required for the proposed enterprise to break even with traditional 24-month bull-beef was $6.84, $6.55 and $5.99/kg for steers slaughtered at 8, 10 and 12 months of age respectively.
New Zealand hill country sheep and beef farms contain land of various slope classes. The steepest... more New Zealand hill country sheep and beef farms contain land of various slope classes. The steepest slopes have the lowest pasture productivity and livestock carrying capacity and are the most vulnerable to soil mass movements. A potential management option for these areas of a farm is the planting of native shrubs which are browsable and provide erosion control, biodiversity, and a source of carbon credits. A bioeconomic whole farm model was developed by adding a native shrub sub-model to an existing hill country sheep and beef enterprise model to assess the impacts on feed supply, flock dynamics, and farm economics of converting 10% (56.4 hectares) of the entire farm, focusing on the steep slope areas, to native shrubs over a 50-year period. Two native shrub planting rates of 10% and 20% per year of the allocated area were compared to the status quo of no (0%) native shrub plantings. Mean annual feed supply dropped by 6.6% and 7.1% causing a reduction in flock size by 10.9% and 11.6...
Hoggets (ewe lambs aged 4 to 16 months) can be bred from approximately 8 months of age for potent... more Hoggets (ewe lambs aged 4 to 16 months) can be bred from approximately 8 months of age for potentially increased flock production and profit, however most New Zealand hoggets are not presented for breeding and their reproductive success is highly variable. Bio-economic modelling was used to analyse flock productivity and profit in four sets of scenarios for ewe flocks with varying mature ewe (FWR) and hogget (HWR) weaning rate combinations. Firstly, hogget breeding was identified to become profitable when break-even HWRs of 26% and 28% were achieved for flocks with FWRs of 135% and 150%, respectively. Secondly, relatively smaller improvements in FWR were identified to increase profit to the same level as larger improvements in HWR. Thirdly, a high performing flock with FWR and HWR both ≥ the 90th percentile currently achieved commercially, was the most profitable flock modelled. Fourthly, a FWR was identified with which a farmer not wishing to breed hoggets could have the same profi...
Breeding hoggets (ewe lambs aged four to 16 months) at 8 to 9 months of age has a number of poten... more Breeding hoggets (ewe lambs aged four to 16 months) at 8 to 9 months of age has a number of potential benefits, including increased lamb production and profitability. However, the majority of hoggets in New Zealand are not bred due to producer concerns regarding their variable reproductive success and increased feed demand. Simulation modelling was used to quantify effects of hogget breeding on sheep numbers, lamb production, sheep feed demand, and sheep enterprise cash operating surplus (COS) compared with a flock not breeding hoggets. Hogget weaning rate (HWR) was modelled at 0%, 60%, 80%, and 100% and combined with mature ewe flock weaning rates (FWR) of 132% and 150%, while maintaining total annual sheep feed demand. For each FWR, increased HWR reduced total sheep numbers, increased the proportion of sheep feed demand for lamb production, increased total numbers of lambs weaned, and increased COS. Therefore, achieving even a relatively low HWR of 60% can improve sheep enterprise...
Considering the current low prices for coarse wool (fibre diameter > 30 µm), a grading up tran... more Considering the current low prices for coarse wool (fibre diameter > 30 µm), a grading up transition to a shedding flock may eliminate wool harvesting costs and increase sheep farm profit. This transition could be achieved by breeding non-shedding ewes with Wiltshire rams. A bio-economic system-dynamics model of a pastoral sheep farming enterprise was used to simulate this grading up transition from 2580 Romney ewes to a similarly-sized flock of fully shedding third or fourth cross Wiltshire–Romney ewes. The total annual sheep feed demand was constrained within a ±5% range to minimise disruption to the on-farm beef cattle enterprise. Wool harvesting expenses were eliminated after seven years of transition, and with reduced feed demand for wool growth, the post-transition shedding flocks had more ewes producing more lambs and achieving greater annual profit compared with the base Romney flock. The net present values of transition were 7% higher than the maintenance of the base Rom...
Uploads
Papers by Peter Tozer