Medicine and Health 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.

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 …

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.

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.

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.

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.

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 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 …

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.

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.

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

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 …

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 …

Annual Ryegrass Toxicity Research Update, A G P Brown, P. Vogal

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

Annual ryegrass toxicity (ARGT) is a complex disease that kills sheep and cattle grazing pastures which contain infected ryegrass. The disease results when a nematode (Anguina agrostis) and a batcerium (Corynebacterium sp.) invade annual ryegrass and cause the seed heads to become toxic as the grass dries off.

The bacterium produces a complex toxin of 18 glycolipid compounds or corynetoxins which have been found to be virtually identical to the antibiotic tunicamycin.

Atrophic Rhinitis In Pigs, A R. Mercy

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

Severe atrophic rhinitis in pigs recurred recently in Australia after an apparent absence of some 20 years. The first of these recent cases occurred in a Westerm Australian herd in late 1984 and since then six other local herds have reported the disease. Severe atrophic rhinitis has also been seen recently in South Australia.

Atrophic rhinitis is a complex disease which causes degeneration of the nasal cavity, twisting of the snout and sometimes occasional bleeding from the nose.

It occurs only in pigs and severely affected animals may have a slower growth rate.

Preventing Lupinosis With Phomopsis-Resistant Lupins, Jeremy G. Allen, W. A. Cowling

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

Lupinosis is one of the major livestock siseases in Western Australia. It is caused by stock eating toxins produced by the fungus Phomopsis leptostromiformis which colonises the stems of dead lupin plants.

In 975, the Department of Agriculture started a breeding programme to develop Phompsis-resistant lupins to overcome or control lupinosis. In the previous issue of this Journal the results of small plot evaluations of new lines of Phompsis-resistant lupins developed in this programme were reported. This article describes the first trial involving grazing of Phompsis-resistant lupins.

A Survey Of Drench Resistance In Sheep Worms, J R. Edwards, R. Wroth, G. C. De Chaneet, R. B. Besier, J. Karlsson, P. W. Morcombe, D. Roberts, G. Dalton-Morgan

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

Sheep worms which are resistant to chemical drenches have been detected with increasing freuency is Western Australia's south-western farming areas between 977 and 1980. These worms have anthelmintic resistance and such genetis resistance puts essential internal parasite control practices at risk.

This prompted veterinarians in the Esperance, Albany, Bunbury, Geraldton and Northam areas to survey farms to determine the prevalence of resistance to drenches and to define those sheep management practices which encourage its development.

This article describes the survey which was conducted to assess the extent of drench resistance, what causes its build-up and how it can be controlled …

Lupinosis : A Disease Still With Us, Jeremy G. Allen, P. Mcr. Wood, K. P. Crocker, J. Hamblin

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

Current research on lupinosis continues to reveal what a complex problem it is, but the improved understanding should help to reduce losses.

Controlling Annual Ryegrass Toxicity, C H. Trotman

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

Eight years of intensive work has changed annual ryegrass toxicity from an unknown killer to a manageable problem.

The Philosophy Of Drenching Sheep In Western Australia, G C De Chaneet

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

Sheep of all classes are drenched more or less regularly throughout the agricultural areas of Western Australia.

Much of the drench is wasted because it is used in the wrong circumstances. This situation is probably a result of poor understanding of drenching.

This article discusses the philosophy of drenching and attempts to relate this to the epidemiology of parasitism as it is currently understood.