Veterinary Medicine Commons^™

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 …

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 …

Bulletin No 4101 - Flystrike - A Manual For Its Prevention And Control, N Monzu Dr

Bulletins 4000 -

The sheep blowfly is still regarded as the Australian sheep industry's most­damaging pest. Estimates of the cost to the industry, through production losses and prevention and control measures, exceed $ I 00 million in a year. This bulletin comprises the most relevant information available on:

• Blowfly types and life cycles

• Conditions predisposing sheep to flystrike

• The mechanism of flystrike

• Methods of preventing and controlling strike.

• Current research - including the development of a forecasting system for body strike.

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 …

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 …

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 …

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 …

Diagnosing Pregnancy In Sheep : The 'Scanopreg', R H. Wroth, M. J. Mccallum

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

The "Scanopreg", an ultrasonic machine for diagnosing pregnancy in sheep, is effective as early as eight to nine weeks of pregnancy, and could therefore be a useful management tool.

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.

Some Basic Facts About Primary Blowflies, N Monzu

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

Research has begun on blowfly species attacking sheep in Western Australia. Already this research has indicated the importance of a species in Western Australia which is not a problem in the Eastern States.

Future management of sheep flocks to minimise fly strike may require recognition of the differences between blowfly species. This article gives a description of the primary species - those which can initiate strikes.

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.

Lumpy Wool May Increase By Dipping : Research Roundup, Department Of Agriculture, Western Australia

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

Lumpy wool, or mycotic dermatitis, is an infectious disease on the skin of the sheep caused by the bacterium Dermatophilus conglensis. The organism invades the wool and hair follicles, causing formation of skin lesions producing scabby material which binds the wool fibres into a hard mass.

Research shows that 'dipping' may increase the incidence of lumpy wool with some chemicals a greater risk than others.

A Survey Of Shearing Times, B R. Beetson

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

When do farmers in W.A. shear their sheep, and why do they selest the times they do?

A Department of Agriculture survey attempted to answer these questions, which have important implications for the wool industry.

Lupinosis And Rates Of Stocking Of Lupin Stubbles, K P. Croker, J. G. Allen, C. R. Lester, R. B. Guthrie

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

Lupin stubbles provide valuable summer sheep feed but under some conditions the fungus Phomopsis rossiana (for which lupins are the host plant) produces a toxin that causes lupinosis. Results from research at Badaingarra Research Station over the 1973-74 and 1974- 75 summers have shown that sheep liver damage associated with lupin stubble grazing is likely to be more severe at high than low stocking rates.

Sheep Fertility In Western Australia, R J. Lightfoot

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

Why do one-quarter of the ewes that are joined in W.A. fail to lamb? Sheep and Wool Adviser Dr. R. J. Lightfoot analyses the eight stages in sheep reproduction, explaining the causes and possible prevention of infertility at each stage.

Pasture Legume Varieties And Ewe Fertility, T Marshall, H. E. Fels, H. G. Neil, R. C. Rossiter

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

ALTHOUGH it was first thought that all varieties of subterranean clover would cause ewe infertility, research in the last 10 to 15 years has shown that varieties differ in potency.

The relative level of potency has also been shown to remain consistent for any one variety under normal conditions.

Mycotic Dermatitis (Lumpy Wool) Of Sheep, M R. Gardiner

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

MYCOTIC dermatitis is a common disease of the skin and overlying wool of sheep (and other herbivorous animals).

The photographs show the typical crusts and scabs which result from infection of skin, hair and wool follicles by the mycotic dematitis organism.

This article reviews the causes of lumpy wool infection and sets out control measures.

Mulesing : Still The Best Weapon Against Fly-Strike, R A. Mills

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

IN SPITE of modern chemicals and insecticides, blow-fly strike remains one of the major problems facing sheep farmers today.

Inoculation Abscesses Can Downgrade Carcasses, M R. Gardiner

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

THE presence of inoculation abscesses in meat is one of the lesser known causes of downgrading or rejection of carcasses, but these abscesses have caused increasing concern in recent years.

They have obvious importance in export carcasses.

A Control Programme For Cheesy Gland In Sheep, M R. Gardiner

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

CASEOUS LYMPHADENITIS, or "cheesy gland" as it is usually known in Australia, is a common disease of sheep which is very important in the economics of the lamb and mutton industry.

High Pre-Mating Liveweights Improve The Lambing Performance Of Merino Ewes, R J. Suiter

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

Analysis of lambing trials with Merino ewes has shown a highly significant association between pre-mating liveweight and lambing performance.

With May-June lambing ewes there was a 2.9 per cent, lambing increase for every extra 10 lb. liveweight; for July-August- September lambing ewes there was a 6.9 per cent, increase for every 10 lb. liveweight increase.

With the May-June lambing there was a critical weight below which twinning was negligible.

Maintaining Ewe Bodyweight For A Late Mating, T Marshall

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

DEPARTMENT OF AGRICULTURE experiments have indicated that the bodyweight of ewes at mating can have a large bearing on lambing performance.

It appears that for every 10 lb. increase in pre-mating bodyweight, an increase of some 3 to 6 per cent, lambs born could be expected, depending on the lambing time.

Later Mating Improves Lambing Results, R J. Suiter

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

Ovulation studies in Western Australia have indicated that increased lambing percentages in crossbred and Merino ewes could be expected from mating in February-April rather than December- January.

Such increases have been demonstrated in time of lambing trials with crossbred ewes, but had not been seen in Merino flocks until recently.

This report summarises the results of time of lambing trials with Merinos carried out at the Merredin and Wongan Hills Research Stations between 1963 and 1969.

Causes Of Low Lambing Percentages, Department Of Agriculture, Western Australia

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

West Australian Merino flocks average about 70 per cent, lambs marked each year. Reasons for this low percentage are that as many as 30 per cent, of ewes do not lamb, twinning rates are low and from 10 to 25 per cent, of lambs born die.

Among the research projects by the Department of Agriculture's Sheep and Wool Branch have been a number directed at the various stages of reproduction in the ewe. These have given some important leads on the causes of low lambing percentages.

If you have marked less than 60 per cent, lambs in the past several …

Are Bactericides Necessary In Sheep Dips?, M R. Gardiner

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

THE OCCURRANCE of mycotic dermatitis in sheep in Western Australia, although rather unpredictable, is quite frequent throughout the higher rainfall districts.

Efforts have been made for several years to control infection by adding bactericides to dips.

Sheep Drenching Programms, Department Of Agriculture, Western Australia

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

Drenching of sheep to prevent build-up of worm infestations is commonly practised on many properties in the agricultural districts of Western Australia. This is called strategic drenching.

Sheep Worm Control And Lambing Time In High Rainfall Areas, F C. Wilkinson

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

Indications from a continuing sheep trial at Margaret River are that farmers in high rainfall areas could increase stocking rates and lamb growth rates by lambing in September- October rather than July-August.

The results also indicate that farmers in the area may be spending more than necessary on worm control.

Drenches For Treatment And Control Of Worms In Sheep : 1969 : Efficiency, Cost And Safety, W A. Halhead, G. De Chaneet

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

THERE is a wide variation in the efficiency and cost of drugs for worm control in sheep.

Generally, the higher the efficiency, the greater the cost. Prices are subject to change, and may vary with the amount of drench purchased.