Life Sciences Commons^™

Re-Thinking The Summer Drenching Program, Brown Besier

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

The summer drenching program has provided highly effective sheep worm control in Western Australia for many years - but recent research challenges its long term sustainability.

Trial results suggest that in large parts of the State, summer drenching is the main factor leading to the development of drench resistant worms. Alternative programs less likely to lead to drench resistance will require greater monitoring of worm burdens and panning pasture moves.

Eradicating Virulent Footrot From Western Australia, R K. Mitchell

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

Western Australia has a unique opportunity to eradicate virulent footrot from the State's sheep flock, with only 62 properties or 0.6 per cent of sheep properties currently in quarantine. The majority of Western Australian flocks are now free of virulent footrot, with targeted on-farm and abattoir surveillance used to detect the remaining properties affected by the disease. Bob Mitchell reports on how farmers, industry, and government are working together, with research playing an important part in the eradication campaign.

Virulent Footrot : Mild Or Severe?, Laurie Depiazzi

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

The footrot eradication scheme in Western Australia has resulted in a low prevalence of severe footrot.

To appreciate the achievement, we need to understand what exactly is being eradicated. 'S' strains of Dichelorbacter nodosus, the infectious bacterium of footrot, are the target of footrot eradication. Laurie Depiazzi examines the basis for eradicating 'S' strains.

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.

Ai : Artificial Insemination Of Sheep, David Windsor

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

Artificial insemination (Al) is used widely in the dairy and beef industries and often performed by farmers themselves. By contrast, sheep breeders generally require assistance from vets when frozen semen is to be used. However, recent experiments with frozen semen are indicating that do-it-yourself Al may soon become a reality.

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.

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.

Choosing Shower Dips For Sheep Lice, Tony Higgs, Bob Love

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

The performance of all shower dip chemicals for sheep lice can vary depending on the active chemical and the conditions under which they are used.

Department of Agriculture trials have indicated that the wettable powders coumaphos and magnesium fluorosilicate were less effective at eradicating sheep lice than were synthetic pyrethroid and organophosphate dipping chemicals.

However, failure to eradicate sheep lice may be the result of several factors, many of them related to management.

Do Farmers Really Want To Eradicate Sheep Lice?, Chris Hawkins

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

With the termination of Western Australia's Sheep Lice Eradication Campaign in 1993 farmers' views about the eradication of sheep lice are of greater relevance now than in the past. Lice control now rests with individual farmers and continuing local lice cell groups .

A recent survey of producers in the Moora Shire provides some key insights into farmers' thoughts about sheep lice and their eradication.

Progress Toward Eradication Of Virulent Footrot, Bob Mitchell

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

Western Australia is well placed to eradicate virulent footrot from the State's sheep and goat populations.

Between 1950 and 1993 the proportion of sheep flocks with footrot fell from about 15 per cent to less than 2 percent, and the 1990-92 outbreak has been turned around. One hundred and eighty properties (]. 7 per cent) of flocks, mostly in the high rainfall South-West, are in quarantine for footrot today.

This high level of footrot control is the result of strong support from the sheep industry and years of good cooperation between farmers and the Department of Agriculture.

Western Australia leads …

Understanding The Importance Of Eperythrozoon Ovis Infection In Sheep, Marc Kabay

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

Assigning priorities for research on sheep diseases relies in part on understanding the prevalence and economic impact of each disease.

Eperythrozoon ovis infection in sheep, for example is a common, but not costly, disease.

Are Foxes Serious Predators Of Stock?, Peter Mawson, John Long

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

Commercial farming of goats for mohair, cashmere and meat production is a rapidly developing industry in the south-west of Western Australia.

In this article, the authors discuss the results of two studies conducted by the Agriculture Protection Board in which the levels of predation of kids and lambs by foxes in commercial goat flocks, and an experimental multiple-birth genotype sheep flock in the southwest of Western Australia, were measured.

Getting The Best Out Of Weaner Sheep In The Eastern Wheatbelt, Sally Revell

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

A study of the growth of Merino weaner flocks over summer and autumn in Western Australia 's eastern wheatbelt during 1989 and 1990 has identified efficient weaner management strategies, and provided a basis for future research and extension needs of this area. The average liveweight of several weaner flocks was unexpectedly low at the start of summer. Weaner flocks may need to be supplemented before the start of summer to prevent undue weight loss at this time.

New Technique Joins The Fight Against Footrot, Laurie Depiazzi, Mike Palmer, David Pitman

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

The diagnosis of footrot in sheep and goats is not an easy task. Two main techniques are used for diagnosis - inspection of diseased feet on a farm and laboratory testing of bacteria isolated from foot scrapings. The interpretation of the results obtained by these methods requires a good understanding of the various forms of footrot.

A new laboratory technique has halved the time taken to detect those strains of the bacterium, Bacteroides (Dichelobacter) nodosus, that cause each form of the disease.

Phomopsis-Resistant Lupin Stubbles As Feed For Weaner Sheep, Colin Mcdonald, Keith Croker, Jeremy Allen

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

The breeding of sweet, narrow-leafed lupins with increased resistance to Phomopsis leptostromiformis, the fungus that causes lupinosis in sheep, is a breakthrough for the summer nutrition of weaner sheep. The new resistant varieties, Gungurru for the medium (325 to 450 mm) rainfall areas and Yorrel for low rainfall areas (less than 325 mm), were released by the Department of Agriculture in 1988.

This article discusses progress in a four-year project which is examining liveweight and wool production of weaners grazing Gungurru stubbles.

Veterinary Consultancy Boosts Piggery Profits, Ashley Mercy

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

A pilot Pig Herd Health Management Scheme co-ordinated by the Department of Agriculture has stimulated much increased involvement of veterinarians in the Western Australian pig industry. Co-ordinated by Ashley Mercy, principal veterinary officer (epidemiology) horn 1985 to 1989, the scheme demonstrated the value of having regular visits from veterinary consultants and in implementing programs to prevent disease and production problems occurring in herds.

The Accumulation And Run-Down Of Dieldrin In Wethers Grazed On Paddocks Previously Treated With Dieldrin, Tony Albertsen, Roy Casey, Keith Croker

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

In mid 1987, the organochlorines (O/Cs) DDT, dieldrin, heptachlor and chlordane were deregistered for agricultural and horticultural use in Australia. These chemicals had been used widely, and land on several hundred Western Australian farms, particularly where potatoes had been grown, was contaminated with chemical residues. Livestock grazing pastures on such land was also contaminated, and our beef exports were threatened. In 1988, the Western Australian Department of Agriculture started a two-year project to collect information from sheep which were grazed on land that had previously been treated with O/Cs, particularly dieldrin. The levels of O/Cs in body and wool fats …

Biological Control Of Doublegee, Dane Panetta

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

Doublegee (Emex australis) is one of the worst agricultural weeds in Western Australia. To date, however, biological control of this weed has proved elusive. Multiple releases of two weevils which attack doublegee have not led to insect establishment. For one of these species, further research has shown that doublegee control would probably not be achieved in the wheatbelt even if insect establishment were enhanced by growing its host during the summer months. A joint Western Australian Department of Agriculture/ CSIRO project is investigating the virulence and host specificity of an undescribed South African species o/Phomopsis fungus. Should this pathogen prove …

The Live Sheep Export Industry, Richard Norris, Barry Richards, Tony Higgs

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

Australia's live sheep trade to Middle Eastern countries is an important export industry. However, about 2 per cent of the sheep die, mainly during the sea voyage. The Western Australian Department of Agriculture has conducted a major research programme to improve the health and welfare of sheep during live export. The programme has'examined many aspects of the export sheep industry, and a substantial part of it has focused on why sheep die during sea transport.

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.

Breeding Phomopsis-Resistant Lupins, John Sylvester Gladstones

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

The release of Gungurru and Yorrel lupins marks the coming of age of the narrow-leafed lupin as a crop plantt. These are the first cultivars of the species th have substantial resistance to Phomopsis stem blight, which will make the stubbles much safer for grazing stock.

This article describes the new lupins, their background, and how they were bred. It also acknowledges the contributions of colleagues who helped in important ways.

Leaf Diseases Of Wheat And Time Of Sowing, J M. Wilson

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

Leaf diseases of wheat can be avoided by delaying the planting of a crop, but this often leads to reduced yield because the benefits of early sowing usually outweigh anylosses caused by leaf disease.

However, it is only in exceptional circumstances that farmers need to consider leaf disease when making decisions about planting date, as this article shows. Most examples are taken from department of Agriculture trials in its northern advisory region, but the principals apply to other agricultural areas.

Weighing Scales For Sheep Do Pay, W D. Roberts

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

Sheep producers can improve production by using weighing scales and keeping accurate records of weights.

Withiut some objective measurement, such as weighing, producers have no accurate method of identifying the heaviest, lightest and average weight of a group of sheep.

They could try to esstimate weight by eye - but most people are poor judges of body weight.

The Sandplain Lupin : Its Nutritional Value And Grazing Management, P W. Morcombe

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

The sandplain lupin or Western Australian blue lupin (Lupinus cosentinii) was introduced to the West Midlands at the turn of the last century. Since that time it has been used as a self-regenerating summer forage for sheep and cattle.

Being deep rooted, it has adapted well to the sandy soils from Perth to Northampton, and plantings now cover more than 100,000 ha.

As few other improved pasture species will persist on these deep sands the sandplain lupin provides an important source of summer feed for grazing livestock. A stand can be grazed throughout summer at stocking rates of 10 to …

Evaluation Of The Crack Approach For The Control Of Drench Resistance In Sheep Worms, J R. Edwards, Helen Chapman, Jon Dunsmore

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

The Department of Agriculture launched the CRACK approach to worm control in September 1985 in response to finding that anthelmintic (drench) resistant worms were present on 68 per cent of a random selection of Western Australian sheep farms.

The high cost of internal parasites in terms of lost production and drench costs, together with the high prevalence of resistant worms of farms, confirmed that changes were needed to existing parasite control measures in sheep.l

Farmers' Estimations Of Sheep Weights To Calculate Drench Dose, R B. Besier, Diane Hopkins

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

Undersosing with drenches is a mojor cause of anthelmintic (drench) resistance in worm parasites of sheep.

When farmers use a drench at less than the recommended dose rate, some worms may survive, and their ability to resist treatment with the chemical involved is passed to their offspring. Over a period of time, matings between worms with different degrees of resistance can produce individuals able to resist the drench at the recommended dose rate or even higher.

Farmers must use adequate dose rates so that worms do not have a chance to survive treatment.

Economic Impact Of Growing Phomopsis-Resistant Lupins, J M. Warren, Jeremy Allen, Wallace Cowling

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

The planting of Phomopsis-resistant lupins will increase net farm income. They will also alter the traditional blend of pastures and cropping, depending on grain and wool prices. In mixed farming areas of Western Australia's southern wheatbelt, they will allow more land to be sown to lupins rather than cereals on farms in which the lack of sheep feed over summer severely restricts wool production.

The benefits of Phompsis-resistant lupins arise from a reduction in sheep deaths due to lupinosis, a longer safe grazing period (free from lupinosis) on lupin stubbles, a decrease in the need for supplementary sheep feed over …

Sheep Lice : Prospects For Eradication, F C. Wilkinson

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

Sheep biting lice have been controlled over the past 86 years in Western australia by a combination of routine insecticidal treatment after shearing and action by the department of Agriculture officers under legislation.

In July 1987 the sheep industry and the State Government will implement a plan to eradicate lice from sheep flocks in the agricultural areas and eventually in the pastoral areas. To achieve this the co-operation of many sectors of the industry will be required. Assuming co-operation is forthcoming, it is possible that by 1996 wool from agricultural areas will be free of lice and insecticidal treatment form …

Survival Of Lambs, R W. Kelly, David Lindsay

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

Between one in every five or six lambs that are born each year in Western Australia die at or about the time of birth. This represents a loss approaching two million lambs and is arguably out single greatest wastage in sheep production. The deaths have an immediate impact on lambing performance and therefore lamb sales, and ultimately effects on such areas as selection of breeding replacement stock, the proportion of ewes and weathers that can be run in a self-replacing flock and the amount of wool produced and its uality.

This article summarises information on what influences lamb survival, and …

Clover Infertility Of Sheep : Continuing Problem, N R. Adams, Keith Croker

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

Some varieties of subterranean clover, notably Dinninup, Dwalganup and Yarloop, contain compounds which act like the female sex hormone oestrogen. These plant oestrogens, or "phyto-oestrogens", interfere with the fertility of sheep and depress the percentage of lambs born.

Over the past 10 years our understanding of clover infertility has increased, and we can now gauge the extent of this residual problem. In fact, there is a widespread but low-level incidence of infertility which does not greatly affect individial farms but which has an important impact on the State's sheep production.