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Full-Text Articles in Physical Sciences and Mathematics

Finfish Aquaculture In Western Australia, David Berry Jan 1997

Finfish Aquaculture In Western Australia, David Berry

Journal of the Department of Agriculture, Western Australia, Series 4

David Berry surveys fish farming from Broome to Williams, on off shore reefs and in farm dams, for barramundi, silver perch and black bream, trout and tuna.


Improving Dairy Farm Performance, Ruth Dilley Jan 1996

Improving Dairy Farm Performance, Ruth Dilley

Journal of the Department of Agriculture, Western Australia, Series 4

Western Austraian sairy farmers produce more milk per cow and per farm than their eastern Sttates counterparts and the milk is also of higher quality. But there is always room for improvement and as grain prices rise it is crucial that maximum benefit is derived from the cheapest feed source - the pasture.With this in mind Ruth Dilley looks at the Dairy Farm Performance Program - a comprihensive farm database developed by Agriculture Western Australia.


Something Fishy Is Going On - Aquaculture, David Berry Jan 1996

Something Fishy Is Going On - Aquaculture, David Berry

Journal of the Department of Agriculture, Western Australia, Series 4

Aquaculture id Australia's fastest growing primary industry. Product from fish farms is currently valued at $399 million, forecast to exceed $5oo million by 2000.

Whilst the figure pales into insignificance alongside world production (about $45 billion) it does represent a huge window of opportunity for prospective investors and for Australian primary producers who are keen to diversify.

David Berry reports on the prospects for yabbie and marron farming in Western Australia.


Value Of Saltbush Questioned, Brian Warren, Tess Casson, Ed Barrett-Lennard Mar 1995

Value Of Saltbush Questioned, Brian Warren, Tess Casson, Ed Barrett-Lennard

Journal of the Department of Agriculture, Western Australia, Series 4

Over the last 20 years the Department of Agriculture has focused on finding plant species that can grow on salt/and to produce sheep feed, and on techniques for establishing plantations of saltbushes. Some research has been in response to farmer reports of success in using revegetated salt/and to provide autumn forage, while other work has resulted from the apparent importance of saltbushes in rangeland areas.

Objective measurements of wool production have been taken only recently. Three years research at Katanning indicates that while saltbush material is selected and eaten by sheep, its value for wool production is not high. It …


Sharing Information Benefits The Meat Industry, Michael Paton Jan 1995

Sharing Information Benefits The Meat Industry, Michael Paton

Journal of the Department of Agriculture, Western Australia, Series 4

Cronic health problems of livestock, seldom detected on farms, reduce the efficiency of abattoirs and returns to producers. But a major project providing information to producers from abattoirs is indicating how everyone could benefit from feedback.


Storm : [Wind Erosion In The Great Southern], Dan Carter Jan 1995

Storm : [Wind Erosion In The Great Southern], Dan Carter

Journal of the Department of Agriculture, Western Australia, Series 4

On Thursday 11 May 1995, a low pressure system with central barometric pressure of 990 hPa formed of south-western Australia. This depression directed gale force winds over the South-West Land Division for some seven hours.

Dan Carter reports on the widespread damage to soils and property, and management practices that would have reduced the problem.


Lupin Stubbles : Getting The Best With Weaner Sheep, Keith Croker, Colin Mcdonald, Jeremy Allen Jan 1994

Lupin Stubbles : Getting The Best With Weaner Sheep, Keith Croker, Colin Mcdonald, Jeremy Allen

Journal of the Department of Agriculture, Western Australia, Series 4

Sweet lupins are now grown on about a million hectares in Western Australia each year. If half of the State's seven million weaners were grazed as recommended on half of the lupin stubbles, it could generate about $15 million from reduced supplementary feeding, greater wool production and other advantages. But correct management is important, particularly knowing when to take weaners out. Research by the Department over the last five years is now indicating how this should be done.


Careful Clip Preparation Will Increase Profit, Peter Metcalfe, Ric Collins Jan 1994

Careful Clip Preparation Will Increase Profit, Peter Metcalfe, Ric Collins

Journal of the Department of Agriculture, Western Australia, Series 4

The current wool market has forced wool growers into producing the maximum number of kilograms of quality wool for the least cost. Preparation of the clip is now much more important to maximise possible net returns. Careful clip preparation will ensure that growers receive the maximum overall average price for each kilogram of wool in the clip.


How Sustainable Is Grazing Sheep On Annual Pastures In The Woolbelt?, Don Mcfarlane, Richard George Jan 1994

How Sustainable Is Grazing Sheep On Annual Pastures In The Woolbelt?, Don Mcfarlane, Richard George

Journal of the Department of Agriculture, Western Australia, Series 4

Low wool prices have reduced the profitability of producing wool from clover-based annual pastures in the south-western woo/belt. The heavy reliance on one commodity is economically unsustainable for many farmers. But we should also consider how ecologically sustainable the practice is.

Shallow-rooted annual pastures contribute to widespread salinity in the area, annual legumes are acidifying the soils and making them water repellent, and bare, detached soils from heavy grazing cause sheet and rill erosion during autumn storms. In addition, stock are degrading remnant vegetation and destroying the soil's structure.

To counteract this degradation, the woo/belt needs more perennial pastures and …


Getting The Best From The Woolbelt, Department Of Agriculture And Food, Western Australia Jan 1994

Getting The Best From The Woolbelt, Department Of Agriculture And Food, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Articles in this issue of the Journal of Agriculture discuss prospects for the wool industry and strategies for wool growers to increase their income and their long term viability.

The impact of low wool prices is greatest in the 'woo/belt' (see map) and the southern pastoral region. There is a need to boost the profitability of wool production and to increase income from sources other than wool in these regions.

The Productivity and Diversification Initiative for Wool Growers is refocussing Department of Agriculture resources to assist wool growers reduce costs, increase productivity and diversify into alternative enterprises.

The strategies recommended …


Quality Wool Production At Lower Cost, Peter Metcalfe Jan 1994

Quality Wool Production At Lower Cost, Peter Metcalfe

Journal of the Department of Agriculture, Western Australia, Series 4

Low wool prices are forcing farmers to reduce their sheep management costs but, fortunately, cost cutting is not resulting in lower wool production, poorer wool quality or lessened sheep care on the best wool growing properties.


Sheep And Wool Industries Need To Improve Their Performance, Rob Kelly, Tim Marshall Jan 1993

Sheep And Wool Industries Need To Improve Their Performance, Rob Kelly, Tim Marshall

Journal of the Department of Agriculture, Western Australia, Series 4

Today in Western Australia, sheep are run at slightly higher stocking rates, are achieving greater lambing percentages (up JO per cent) and higher wool cuts per animal ( up 0. 6 kg greasy) than in the 1960s. When all components of production are considered, the productivity of sheep fanns has increased by 2. 7 per cent per year over the past 35 years.

The challenge of the next decade is to achieve substantially greater rates of improvement than for past years if the sheep and wool industries are to maintain their significant place in Western Australian agriculture.


Red Kangaroos Can Set Back Range Regeneration, Andrew Mclaughlin Jan 1992

Red Kangaroos Can Set Back Range Regeneration, Andrew Mclaughlin

Journal of the Department of Agriculture, Western Australia, Series 4

After years of severe drought, stocking rates in Western Australia s arid rangelands have been kept low since the 1970s to allow native pastures to regenerate. As well, extensive re-seeding programs have started and sheep and cattle grazing on these areas has been restricted or eliminated. However, pasture regeneration in the rangelands can only succeed when grazing by all animals - sheep, cattle, kangaroos, goo.ts, camels, brumbies and donkeys - is controlled Many more red kangaroos roam throughout Western Australia's pastoral areas today than 20 years ago. The installation of windmills and troughs to water domestic livestock has allowed kangaroo …


Taking The Emu To Market, Paul Frapple, Ruth Hagan Jan 1992

Taking The Emu To Market, Paul Frapple, Ruth Hagan

Journal of the Department of Agriculture, Western Australia, Series 4

Licensed, commercial emu farming in Western Australia is now five years old.

This year, 13,500 birds will be processed for their meat, skin and oil. Production has exceeded demand at prices which the industry considers fair because the industry is still developing marketd for these producys.

Without secure, long term markets, over-production will worsen as the turn-off in this State increases and emus become available from other Australian states and overseas.

The Department of Agriculture is assisting the industry to develop a viable industry.


How Arsenic Residues Get In Wool, Tony Martin, Robin Jacob, Marion Davies, Peter Rutherford Jan 1992

How Arsenic Residues Get In Wool, Tony Martin, Robin Jacob, Marion Davies, Peter Rutherford

Journal of the Department of Agriculture, Western Australia, Series 4

Wool can become contaminated with arsenic in various ways, and several different sources may each contribute to any individual arsenic residue problem.

• dipping sheep in an arsenical dip ( now illegal),

• dipping sheep in a non-arsenical dip in a contaminated dipping facility

• penning sheep on soil with high levels of arsenic before shearing.

Other possible sources include running sheep on land contaminated by gold mine tailings or exploration sites, and allowing sheep access to sites on the farm where arsenical compounds have been dumped, for example, rubbish dumps or sites where dip/sump sludge has been dumped.

Farmers …


Survey Of The Damage Caused To Trees By Goats, Steve Gherardi, Dick Mills, Tim Johnson Jan 1991

Survey Of The Damage Caused To Trees By Goats, Steve Gherardi, Dick Mills, Tim Johnson

Journal of the Department of Agriculture, Western Australia, Series 4

The damage that goats can cause to trees is one of the major problems associated with their farming in the agricultural areas of Australia. It is also considered one of the main hindrances to the development of the goat industry. The Department of Agriculture s Goat Industry Development Unit surveyed mohair and cashmere producers to determine the prevalence of tree damage and its extent and severity; why producers believed goats damaged trees; and how producers minimised or prevented this damage.


Trees And Livestock : A Productive Co-Existence, Richard Moore Jan 1991

Trees And Livestock : A Productive Co-Existence, Richard Moore

Journal of the Department of Agriculture, Western Australia, Series 4

Trees, as part of farming can help to combat land degradation problems and produce a good economic return from timber at the same time. For example, there is now clear evidence that planting trees can help combat salinity by lowering water-table levels. Trees can also substantially improve overall farm productivity by providing shelter for pastures and livestock. The challenge is to find practical and economical methods of integrating trees and farming. A combination of widely-spaced trees and livestock is one promising method. This article describes the benefits of this type of agroforestry to farmers, suitable locations and how to practice …


Can Kangaroos Survive In The Wheatbelt?, Graham Arnold Jan 1990

Can Kangaroos Survive In The Wheatbelt?, Graham Arnold

Journal of the Department of Agriculture, Western Australia, Series 4

One of the costs of agricultural development in Western Australia over the past 100 years has been the loss of most of the native vegetation and, consequently, massive reductions in the numbers of most of our native fauna. Thirteen mammal species are extinct and many bird and mammal species are extinct in some areas. These losses will increase as remnant native vegetation degrades under the impact of nutrients washed and blown from farmland, from the invasion by weeds and from grazing sheep.

Even kangaroos are affected. Unless the community manages remnant vegetation to minimise degradation and enhance the regeneration of …


Finishing Kimberley Cattle In The South-West, Brian L. Mcintyre, Bill Ryan, Neville Macintyre Jan 1989

Finishing Kimberley Cattle In The South-West, Brian L. Mcintyre, Bill Ryan, Neville Macintyre

Journal of the Department of Agriculture, Western Australia, Series 4

The idea of integrating the Kimberley cattle industry with that in the south-west of Western Australia is no new, but until recently it had not been critically evaluated.

Over the past eight years the Department of Agriculture's Beef Cattle Branch has been assessing the performance of Kimberley cattle transported south for finishing in the agricultural areas.

This research has show that Kimberley weaners can be finished in the south, and that under the present (December 1988) economic conditions it is more profitable than running breeding cattle in the south-west and comparable with fattening store steers.


Erosion Potential Of Phomopsis-Resistant Lupins, D J. Carter, Paul Findlater Jan 1989

Erosion Potential Of Phomopsis-Resistant Lupins, D J. Carter, Paul Findlater

Journal of the Department of Agriculture, Western Australia, Series 4

During lupin harvesting, up to 20 per cent of the grain remains on the ground. This non-harvested or pilt grain is a valuable feed for sheep during early summer because the pods, leaf and stem generally provide little nutrient in the stubnbles. In addition, the more efficient the weed control, the less valuable are the stubbles.

The disease lupinosis caused by Phomopsis leptostromiformis restricts the amount of grazing from the lupin stubbles, and hence the risk of wind-erosion of stubble paddocks.

However, the introduction of lupin varieties moderately resistant to Phomopsis and with reduced potential to cause lupinosis means that …


Intensive Animal Industries In The Peel-Harvey Catchment, R W. Payne Jan 1989

Intensive Animal Industries In The Peel-Harvey Catchment, R W. Payne

Journal of the Department of Agriculture, Western Australia, Series 4

The Swan coastal plain to the north and south of Perth is attractive for the intensive production of pigs and poultry for several reasons. It is close to markets, feed manufacturers and labour; has a less extreme climate than inland areas; and is underlain by a large reserve of high quality groundwater.

Because these are all intensive operations, large quantaties of nutrient-rich waste are produced over a very small area. They can severely damage ground and surface waters unless steps are taken to control the wastes which they produce.

This article oulines both the nature of intensive aniamal industries in …


Choosing A Calcium Supplement For Sheep Fed Cereal Grains, R L. Peet, Michael Hare Jan 1989

Choosing A Calcium Supplement For Sheep Fed Cereal Grains, R L. Peet, Michael Hare

Journal of the Department of Agriculture, Western Australia, Series 4

Sheep fed cereal grains as an energy source over summer usually need added calcium because cereal grains are generally low in calcium (for example, 0.03 per cent calcium compared to 0.26 per cent phosphorus), and there may not be a natural source such as clover, weeds, leafy stubble or edible bush in the paddock.

The safestt and most effective calcium supplement is finely ground limestone added to the feed, but some farmers have used other sources of calcium such as gypsum and superphosphate in this manner.


Production From Heifers And First Calvers, G J. Sawyer Jan 1987

Production From Heifers And First Calvers, G J. Sawyer

Journal of the Department of Agriculture, Western Australia, Series 4

Heifers and first calvers present the major problems of the beef breeding herd. Reproduction rates, calf growth and survival of first calvers are generally much poorer than those of adult breeders.

Early successful reproductive performance is important in beef herds because of the high overhead cost of keeping breeding beef heifers or cows, Where possible, beef producers should aim to join heifers at 14 to 15 months of age. To achieve this goal, producers should set production targets for those animals. These targets will differ from farm to farm depending on when calves are turned off and the seasonal feed …


Dust Elimination From Outdoor Feedlots For Sheep, D J. Carter Jan 1987

Dust Elimination From Outdoor Feedlots For Sheep, D J. Carter

Journal of the Department of Agriculture, Western Australia, Series 4

The humble woodchip, widwly used as a soil mulch in Western Australian gardens, is set tto take a new role as a dust inhibito in assembly yards used to hold live sheep for export.

Research by the Department of Agriculture's Soil Conservation Service Branch has shown that, of the materials tested, woodchips were the most effective in preventing dust being generated. Wind speeds had to approach a "near gale" before dust developedfrom the protected soil.

The use of woodchips, therefore, provides a practical alternative to stabalising the soil and preventing an environmental problem associated with one of the State's valuable …


Grazing And Management Of Saltland Shrubs, C V. Malcolm, J. E. Pol Jan 1986

Grazing And Management Of Saltland Shrubs, C V. Malcolm, J. E. Pol

Journal of the Department of Agriculture, Western Australia, Series 4

areas of bare saltland on farms need not be unproductive etesores. Many Western Australian farmers are now successfully growing salt-tolerant or halophytic shrubs such as bluebush (Maireana brevifolia), saltbushes (Atriplex spp.) and samphires (Halosarcia spp.) on these areas.

Department of agriculture trials and farmers' experience indicate that if saltland is planted with recommended shrubs, it can provide two months' valuable grazing for sheep during autumn and early winter, a time when paddock feed is scarce. Research by the Department has also identified a range of salt-tolerant shrubs suited to the various types of saltland.

Grazing trials to …


Feral Donkeys : An Assessment Of Control In The Kimberley, S H. Wheeler Jan 1984

Feral Donkeys : An Assessment Of Control In The Kimberley, S H. Wheeler

Journal of the Department of Agriculture, Western Australia, Series 4

Feral donkeys are one of the major limitations to increased pastoral production in many parts of the Kimberley area of Western Australia, where they compete with cattle for food. In addition donkeys are aggressive animals, driving cattle from watering points and better grazing areas. They eliminate perenial plants by overgrazing and therefore reduce the carrying capacity of the range.

Originally introduced as draught animals, donkeys were released when cars arrived; since then they have bred up to large numbers in many areas.

For several years the Agricultural Protection Board has undertaken a programme of donkey shooting from helicopters. Since this …


Rabbit Kitten Survival In The South-West, D R. King Jan 1984

Rabbit Kitten Survival In The South-West, D R. King

Journal of the Department of Agriculture, Western Australia, Series 4

In the South-West of Western Australis reliable winter rains allow the rabbit breeding season to extend through winter and spring, and thus a large number of kittens are produced each year.

Studies on the biology of rabbits at Cape Naturaliste (270 kilometres south-west of Perth) and Chidlow (40 kilometres east of Perth in the Datling Range) have shown that at these sites each doe produces about 30 and 27 kittens respectively a year. If all these youg rabbits survived, there would be a 15-fold increase in numbers. Within a short time the State would be covered "wall to wall" by …


Myxomatosis In Western Australia, D R. King, S. H. Wheeler Jan 1984

Myxomatosis In Western Australia, D R. King, S. H. Wheeler

Journal of the Department of Agriculture, Western Australia, Series 4

Since myxomatosis was introduced to Western Australia in the early 1950s rabbit plagues have ceased. However, myxomatosis has not proven to be the whole answer to the rabit problem.

Rabits continue to damage crops and pastures in many areas and resurgences of rabbit populations are reported from time to time.

Drs D.R. King and S. H. Wheeler of the Agricultural Protection Board's research section have been studying the way myxomatosis epidemics occur and spread in rabbit populations in a range of Western Australian environments. This research will provide data for planning effective control strategies intergrating the various control options available …


Rabbits North Of Carnarvon, D R. King Jan 1984

Rabbits North Of Carnarvon, D R. King

Journal of the Department of Agriculture, Western Australia, Series 4

In Westeern Australia rabbits are mainly a pest along the south-western coastal parts of the State, but there are populations north of the Tropic of Capricorn. Rabbits after crossing the Nullarbour plain from South Australia and colonising the South-West of the State, were reported to have reached the west coast near Geraldton by 1912 and then spread northwards.

There is little information on the biologhy of rabbits in the northan parts of their range, but pastoralists in some areas are concerned about erosion and damage to vegetation on their stations when rabbits reach high numbers.

The Agricultural Protection Board undertook …


Research Objectives In Vertebrate Pest Control, A J. Oliver Jan 1984

Research Objectives In Vertebrate Pest Control, A J. Oliver

Journal of the Department of Agriculture, Western Australia, Series 4

The European rabbit, introduced into Australia in 856 by an early settler for hunting, caused massive losses to agricultural production in Western Australia in 1940s and 1950s.

In those years most of the country's recources and efforts allocated to vertebrate pest problems were aimed at controlling this animal.

Research and control measures by Commonwealth and State agencies, including the introduction of myxomatosis, were largely responsible for reducing the rabbit problem to the comparatively minor one it is now.

Today, the Agricultural Protection Board is involved in the control of a much wider range of mammals and birds which cause losses …