Life Sciences Commons^™

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

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 …

Pollorum Tested Poultry Flocks, 1966-67, Department Of Agriculture, Western Australia

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

PULLORUM disease has been virtually eliminated from breeding and hatchery poultry flocks in Western Australia by the annual blood-testing of all birds and the destruction of reactors.

Dead Lambs : A Dead Loss, Stanley M. Dennis

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

During the past year the Animal Health Laboratory has continued its survey into the causes of abortion in sheep and perinatal lamb losses.

This article records the results of this work.

LAMBS and specimens from lambs were submitted to the Animal Health Laboratory from 229 properties situated in 121 areas in this survey during 1964.

Post-mortem examination was carried out on 1,422 lambs and specimens from 61 lambs were also examined.

More Light On Lamb Losses : Third And Final Report Of A Survey Of Lamb Mortalities In W.A, Stanley M. Dennis

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

DURING the past three years the Department of Agriculture's Animal Health Laboratory carried out an investigation into the causes of perinatal lamb losses.

This article records the results of this work.

Tales From Dead Lambs : Results Of A Survey Of Lambing Losses, Stanley M. Dennis

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

During the past year the Animal Health Laboratory has been conducting a preliminary survey into the infectious causes of abortion in sheep and perinatal lamb mortalities. This work was prompted by:

* The diagnosis of vibrionic abortion for the first time in Western Australia in 1961, and

* The estimate that 30 per cent, of all ewes mated in Australia each year may fail to produce a viable lamb that survives to marking time.

This enormous lamb wastage is due to a variety of causes and the role of infectious agents has yet to be evaluated.