Veterinary Physiology Commons^™

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 …

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 …

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 …

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 …

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.

Pigs May Need More Protein, N W. Godfrey

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

Results of trials indicate that meatmeal based rations of 18 to 20 per cent protein may improve carcase quality and give better returns.

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.

Prevent Worms In Cattle, G C De Chaneet

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

PARASITIC gastro enteritis, caused by roundworms, is a common cause of economic loss in calves, yearlings and occasionally cows in south-western Australia. Losses could be prevented if stock owners realised the full effects of these parasites, and understood the causes of worm infestation.

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.

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.

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 …

Shed Lambing In The Esperance Environment, T Marshall, F. F. Dixon

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

Neonatal lamb mortality is often high in Western Australia and losses as high as 33 per cent, have been recorded on private properties in the Esperance area. Surveys by Western Australian Department of Agriculture officers have indicated that more than threequarters of such lamb deaths occur after birth. About half these deaths result from the combined effects of weather and mismothering.

Work in Victoria has indicated that lamb mortality may be reduced by intensive lambing systems such as shedding and this trial was established to see if shedding could reduce lamb mortality in the Esperance environment.

Two Causes Of Reduced Profit From Pigs, G A L Ward

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

LOSS of condition in a pig affects profits more severely than slow rate of growth.

Two common symptoms, scouring and itching, cause weight loss and are followed by a period of reduced weight gain.

Pendulous Crop Of Turkeys, M E. Bacon

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

THE condition known as pendulous crop occurs occasionally in a mild form in fowls, but the most commonly reported cases concern the classical symptoms that occur from time to time in turkeys.

The condition is also referred to as baggy crop, dropped crop, hanging crop and sour crop, and causes mortality, poor development and emaciation within turkey flocks in some areas.

A Guide To Good Lamb Marking, H E. Fels

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

LAMB marking is the most severe of the various ordeals that sheep are called upon to endure.

It is a series of surgical operations, each involving a risk of infection, and some involving risks of severe haemorrhage.

Growth rate is reduced to the same extent by rubber rings as by the knife.

Reproductive Wastage And The Sheep Shortage In Western Australia, Department Of Agriculture, Western Australia

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

WESTERN AUSTRALIA has an acute shortage of sheep.

It is estimated that about seven million extra sheep are needed to stock existing pastures fully; meanwhile the carrying capacity of the State's pastures is increasing at the rate of three million sheep a year.

The Causes And Control Of Infertility Of Rams, J Craig

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

FACTORS other than physical faults often cause infertility of rams.

Obviously, it is important to distinguish between temporary and permanent infertility to apply the proper remedy.

Ram Management, J Craig

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

REALISING that good rams play an important role in flock improvement, the wise flock owner selects his rams after careful consideration of their breeding, type, production and fleece characters or potential meat-producing qualities.

Good ram management can have a major effect on lambing percentages. In this article Senior Veterinary Surgeon J. Craig outlines methods of achieving the best results from rams.

Weaning And Weaner Management, R J. Lightfoot

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

MOST of Western Australia's Merino flock owners wean their lambs in the months of August, September and October.

Too often this is done indiscriminately to fit in with other operations, or lambs are left on their mothers for long: periods until the ewes are remated.

Keep Your Pigs Cool, P C. Beck

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

CORRECT MANAGEMENT and husbandry of pigs during the hot summer experienced in Western Australia is of the utmost importance if production is to be maintained at a profitable level.