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Summer Drenching Of Sheep : New Recommendations For High Rainfall Areas, Brown Besier, Jill Lyon

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

'Summer drenching' has been a highly successful strategy for controlling sheep worms in Western Australia's winter rainfall regions for many years. Drenching to remove worm burdens in summer, when the risk of reinfection by worm larvae is low, is an efficient basis to year-round worm control. The Department of Agriculture recently altered its recommendations for the timing of summer drenches to take account of new findings regarding the survival of worm larvae over summer. It now recommends that sheep farmers give the first summer drench when the pasture is beginning to dry off, in spring in most locations. Experiments atMt …

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 …

Differences Between Merino Strains And Studs, Roger Lewer

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

When commercial wool growers select Merino rams they often use the following pattern: the buyers first consider the main strains of Merinos in Western Australia - Bungaree, Collinsville and Peppin. They then study the 550 studs and numerous non-stud ram breeders in this State. Having chosen a breeder, they examine the rams on offer and buy their annual requirements from among these. Until recently, no objective information has been available on the differences between studs and strains in Western Australia's agricultural areas. However, as part of a major study at the Department of Agriculture's Great Southern Agricultural Research Institute, these …

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.

New Insights Into The Management Of Ewes Over Summer And Autumn, Rob Kelly, Ian Ralph

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

Recent research in Western Australia has provided new information on the effects of liveweight and liveweight change on wool production and quality, as well as lamb survival and growth. Liveweight and liveweight change in sheep reflect the animals' nutritional status, and this in turn directly influences their wool production and reproductive performance. The under-nutrition of sheep not only has an immediate effect on the animal's performance, but the research showed that it also produces a significant carry-over effect on wool and lamb production, even if the ewes have returned to good feed. These findings suggest that for the efficient management …

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.

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.

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

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.

New Initiatives In Processing Australian Sheep Skins, P G. Frapple

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

Australia's exports of 313 million preserved sheep and lamb skins were valued at $A261.2 million FOB (free on board) in 1986-87. Just over 40 per cent (13.1 million) of these skins went to France for fellmongering, which is the process of removing wool from skins, leaving a bare pelt suitable for tanning. The balance went to other countries including Yugoslavia, Spain and West Germany, mainly for tanning with the wool on.

Computer Model Can Help Wool Producers, K M S Curtis

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

No abstract provided.

The Western Australian Sheep Skin Industry, P G. Frapple

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

Sheep skins are a by-product of livestock production and slaughter. Their supply is determined largely by the demand for meat, rather than the demand for leather and leather products. As a result, skin prices fluctuate widely, as happened from April to June, 1988.

Production From The Management Of Burr Medic Pastures, C W. Thorn

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

No abstract provided.

Cereal Straw And Stubble For Sheep Feed, E M. Aitchison

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

Many farmers in Western Australia run sheep in addition to their cropping programmes. The resulting cereal straws and stubbles are therefore important as sheep feed during summer and autumn. During this period the diet must provide sufficient energy to maintain liveweight, but additional energy and protein may be required for young stock and pregnant or lactating ewes, and to reduce problems from tender wool.

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.

Live Sheep Exports : Market Update, E J. O'Loughlin

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

The live sheep export trade has made an important contribution to the Western Australian sheep industry, with the value of exports peaking at $100 million f.o.b. in 1980-81. In that year Western Australia accounted for 61 per cent of the value of Australian exports of live sheep. In addition, the growth of the live export industry has contribuited to higher prices for other catagories of sheep than would otherwise have been the case.

Feeding Behaviour Of Live Sheep During Export, C L. Mcdonald

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

Live sheep exporters in Western Australia often hold as many as 00 000 sheep in assembly feedlots while the consignment is being purchased and assembled before shipment. During the assembly phase the sheep ane introduced to the pelleted rations used on board.

Industry reports have highlighted the wide variability in condidtions, facilities and procedures used, and showed that there was little evidence from which to make recommendations to the live sheep shipping indudtry. This article discusses ten experiments by the Department of Agriculture from 1981 to 1985 designed to investigate what influences the feeding behaviour of Merino wethers under conditions …

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 …

Reproductive Wastage In Sheep, R W. Kelly

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

The average lambing performance of Western Australia's ewe flock fluctuates between 60 and 70 per cent. Although this level of performance and variation between years is important for the sheep industry, individual farmers are more concerned about performance of their own flocks.

Figure shows the range in lambing performances that exist between farms in this State in 1983-84. The seriously poor performance of many flocks is apparentm - 28 percent of farms had less than 60 per cent lambing. By contrast, 24 farms had performances better than 100 per cent. The reasons for the large differences between farms ( and …

More Lambs From Feed And Chemical Treatments, K P. Croker

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

The ovulation rate, or the number of eggs shed per ovulating ewe, represents the upper limit of the capacity of a flock of ewes toproduce lambs. Several methods can be used to increase ovulation rates and lambing percentages of ewes, including selection for better breeding, feeding and the use of chemicals.

The potential for improving the reproductive performance of Western Australia's ewe flocks by the use of different approaches to breeding was discussed by L.G. Butler and R.P. Lewer in the Journal of Agriculture in 1983.

This article mainly discusses the research conducted by the Department of Agriculture's Sheep and …

Control Strategies For Annual Ryegrass Toxicity, W J. Burdass

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

In 982-83, annual ryegrass tocicity (ARGT) was estimated to have cost Western Australian sheep farmers between $7 and $8 million in total economic losses.

The disease can severely disrupt farming operations. Sheep must be checked daily and if affected moved to a 'safe' paddock. The availability of paddock feed is reduced, as is stock carrying capacity. Worry about the possibility of dramatic stock losses, and uncertainty about what decisions to make, are all stressful.

Stock losses from ARGT can be minimised by the use of selective herbicides to control ryegrass in pastures and crops. This breaks the disease cycle - …

Pregnancy Diagnosis Using Ultrasound, M A C Johns

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

Few Western Australian ewe flocks are diagnosed for pregnancy despite the precence of high numbers of barren ewes. Surveys of farm flocks in the early 1970s recorded that between 14 and 29 per cent of ewes failed to lamb each year.

Techniques for diagnosing pregnant ewes have been available for many years, but ultrasonic devices and computer technology have made it possible for skilled operators to determine whether ewes are pregnant and more importantly, whether they have one, two or more foetuses.

Once the number of pregnant ewes is known farmers can use labour more efficiently. They can minimise the …

Ovulation Rate Of Ewes : Role Of Energy And Protein, E Teleni, J. B. Rowe

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

Western Australia's sheep farmers are familiar with the low ovulation rate of Merino ewes and how this limits the lambing performance of ewe flocks.

One way in which ovulation rate and therefore lambing percentage may be increased is to feed seed of sweet lupin (Lupinus augustifolius) to ewes at mating. However, Department of Agriculture research has found that these increases do not show up consistently, and that there is considerable variability between farms.

If improved nutrition is to be a useful way to increasing ovulation rate, the mechanism by which nutrition affects ovulation rate must first be understood. This article …

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 …

'Dermo' Fleece Rot And Body Strike On Sheep, S G. Gherardi, S. S. Sutherland, N. Monzu

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

Blowfly strike is one of the major problems confronting the sheep industry in Austrsalia, with an estimated totsalcost of control eceeding $100 million each year.

Sheep are susceptible to five types of strike: body, breach, poll, pizzle and wound. Body strike, is of greater economic importance because its sporadic occurence from year to year makes it difficult to predict and cintrol. Outbreaks of body strike after rain can affect large numbers of sheep and inflict severe production losses.

In eastern Australia fleece rot is generally considered to be the main predisposing factor to blowfly strike, but in Western Australia evidence …

Dispelling Some Myths About 'Dermo', J R. Edwards

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

There are a lot of misconceptions and myths about dermatophilosis, a disease which can kill young lambs, affect wool quality, make shearing difficult and make sheep susceptible to fly strike.

One misconception is perpetuated by the incorrect use of the name mycotic dermatitis, which implies that a fungus causes the disease. This is not so.

The disease is caused by the bacteria Dermatophilus congolensis, which attacks the sheep's skin and eventually forms a lesion or scab in the wool, and so is better called dermatophilosis, 'dermo' or 'lumpy wool'.

Veterinary Epidemiologist at the Albany Regional Office, J.R. Edwards, discusses …

Protecting Off-Shears Sheep In Adverse Weather, T M. Ellis

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

In January 2982 in the Narrogin-Darkan area of Western Australia, about 14,500 sheep up to 40 days off-shears died after a 48-hour period of heavy soaking rain that followed a thunderstorm three days previously. An estimated 100,000 sheep died throughout the South-West at the time.

P. G. Buckman - at the time Department of Agriculture District Veterinary Officer, Narrogin - surveyed 17 properties in the area. He found that losses in unshedded sheep 0 to 40 days off-shears ranged from 0 to 84 per cent of sheep on the property with an overall average of 27.9 per cent. Rainfall in …

New Developments In Footrot Control, R B. Richards, L. J. Depiazzi, R. V. R. Gwynn

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

The eradication policy for footrot in sheep adopted by the Western Australian Department of Agriculture has produced an overall decline in the number of properties with the disease.

Our knowledge of the disease has improved substantially as a result of the research conducted at the Slabany Regional Veterinary Laboratory in recent years. Laboratory tests now sssist stock inspectors and veterinary officers to distinguish between different forms of footrot and to quarantine and eradicate accordingly.

The recent discovery of more effective foot-bathing solutions by officers of the Victorian Department of Agriculture will greatly assist further eradication procedures.

Western Australia's sheep industry …

A Survey Of Cattle And Sheep Parasite Control Practices, Department Of Agriculture, Western Australia

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

No abstract provided.

A Grain Feeding Hint : Add Finely Ground Limestone, Peet

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

No abstract provided.