Survey of anthelmintic resistance in Western Australian sheep flocks 1. Prevalence

1986 ◽  
Vol 63 (5) ◽  
pp. 135-138 ◽  
Author(s):  
J R EDWARDS ◽  
R. WROTH ◽  
G C CHANEET ◽  
R B BESIER ◽  
J. KARLSSON ◽  
...  
Keyword(s):  
Anthelmintic Resistance ◽  
Australian Sheep ◽  
Western Australian

The effective life of ivermectin on Western Australian sheep farms—A survival analysis

2005 ◽  
Vol 72 (3-4) ◽  
pp. 311-322 ◽  
Author(s):  
R.J. Suter ◽  
E.J. McKinnon ◽  
N.R. Perkins ◽  
R.B. Besier
Keyword(s):  
Survival Analysis ◽  
Australian Sheep ◽  
Western Australian ◽  
Effective Life

Anthelmintic resistance in sheep nematodes in Australia: the need for new approaches

2003 ◽  
Vol 43 (12) ◽  
pp. 1383 ◽  
Author(s):  
R. B. Besier ◽  
S. C. J. Love
Keyword(s):  
Field Experiments ◽  
Anthelmintic Resistance ◽  
Treatment Resistance ◽  
Summer Rainfall ◽  
Sheep Industry ◽  
South Wales ◽  
Australian Sheep ◽  
Almost All ◽  
Worm Control ◽  
The Impact

Sheep worm infections increasingly threaten the profitability of the Australian sheep industry as the prevalence and severity of anthelmintic resistance continues to rise. Field experiments have demonstrated that the use of drenches that are of reduced efficacy due to resistance can reduce wool production by 10% and significantly reduce sheep sale value. The major factor in benzimidazole (BZ) and levamisole (LV) resistance, and in part macrocyclic lactone (ML) resistance in Haemonchus contortus, is considered to be the excessive frequency of treatment. In Ostertagia circumcincta, ML resistance appears to be related chiefly to interactions between the environment and the time of treatment, where resistant worms surviving drenches are not significantly diluted by worms acquired after treatment. Resistance to the BZs and LV affects almost all Australian sheep farms, and on most drench efficacy is now below a useful level. ML resistance is common in O. circumcincta in Western Australia, and increasingly prevalent in H. contortus in summer rainfall regions. Closantel resistance is a major threat to H.�contortus control in northern New South Wales and southern Queensland. The organophosphate naphthalophos, especially when used in combination with other compounds, has proved useful although variable in efficacy. It is essential that the sheep industry adopts approaches that minimise reliance on chemical control, such as the breeding of worm resistant sheep, use of specific grazing strategies for worm control and apply flock treatment tactics to minimise further resistance development. New non-chemical technologies under development are also expected to contribute to more sustainable worm control. Nutritional regimens that minimise the impact of worm infections and enhance the immune response require investigation and integration into sustainable control practices.

Sarcocystis spp in Western Australian sheep

1993 ◽  
Vol 70 (4) ◽  
pp. 152-154 ◽  
Author(s):  
G. SAVINI ◽  
JD DUNSMORE ◽  
ID ROBERTSON ◽  
P. SENEVIRATNA
Keyword(s):  
Sarcocystis Spp ◽  
Australian Sheep ◽  
Western Australian

scholarly journals A survey of Western Australian sheep, cattle and kangaroos to determine the prevalence of Coxiella burnetii

2010 ◽  
Vol 143 (2-4) ◽  
pp. 337-345 ◽  
Author(s):  
Michael Janis Banazis ◽  
Abbey Simone Bestall ◽  
Simon Andrew Reid ◽  
Stan Gordon Fenwick
Keyword(s):  
Coxiella Burnetii ◽  
Australian Sheep ◽  
Western Australian

Anthelmintic resistance in Australian sheep nematode populations

1994 ◽  
Vol 71 (4) ◽  
pp. 117-121 ◽  
Author(s):  
DJ OVEREND ◽  
ML PHILLIPS ◽  
AL POULTON ◽  
CED FOSTER
Keyword(s):  
Anthelmintic Resistance ◽  
Australian Sheep

Effects of bait age on the number, sex, and age composition of Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) in Western Australian blowfly traps

1994 ◽  
Vol 34 (5) ◽  
pp. 595 ◽  
Author(s):  
WG Vogt ◽  
TL Woodburn
Keyword(s):  
Exposure Time ◽  
Reproductive Age ◽  
Lucilia Cuprina ◽  
Age Composition ◽  
Coefficients Of Variation ◽  
Australian Sheep ◽  
Males And Females ◽  
Gravid Females ◽  
Trap Catches ◽  
Western Australian

Daily catches of the Australian sheep blowfly, Lucilia cuprina, in Western Australian blowfly traps were not significantly affected by exposing the baits in traps for up to 3 days in the field before trapping. Exposure of the baits for longer periods significantly increased the daily catch totals of both sexes. Baits with a mean exposure time before trapping of 7 days (old baits) returned significantly higher catches than baits with a zero exposure time (fresh baits): 5-fold and 3-fold increases, respectively, for males and females. Exposure of baits for only 1 day was sufficient to produce significant changes in the reproductive age composition of female catches; proportions of newly emerged females increased and proportions of gravid females decreased. Coefficients of variation for old bait/new bait catch ratios were small, 16.4% for males and 12.3% for females, which confirmed that both baits exhibited consistent levels of attractiveness on different trapping dates. Procedures are suggested for estimating population densities of L. cuprina based on trap catches using fresh and old baits.

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