How do the Aussies control parasites?

Worms, lice and blowflies are the three biggest health problems for the Australian sheep industry and represent over $700 million in direct and indirect costs to Australian woolgrowers every year.

During September-October 2004, a 10 page questionnaire, asking about worm, blow-fly and lice control practices, was mailed to a random sample of 4,386 sheep producers in the major sheep production regions of Australia. 52.3 percent of producers responded to the survey.

• On average, 44 percent of sheep producers use worm egg counts to monitor the need to drench.
• Those who use worm egg counts, check weaners 3 times per year.
• On average, 48 percent of sheep producers say they have conducted a drench resistance test of some kind, although of these, only 23 percent tested within the last two years.
• Of those testing for drug resistance, only 33 percent said they are using a fecal egg count reduction test or the DrenchRite test, the only recognized drug resistance tests.
• 14 percent of producers use rams selected for resistance to worms as a strategy for controlling worms.
• 20 percent of flocks had lice at their last shearing. 22 percent of producers never treat for lice. 22 percent treat on an as-need basis. 56 percent treat treat for lice annually. Over 80 percent of dips use diazinon.
• 91 percent of Merino sheep are mulesed. Mulesing involves surgically removing the skin around the breech (backside) to prevent wool growth which reduces the risk of fly strike caused by a unique and very aggressive Australian blowfly (Lucilia cuprina).
• The majority of producers (61%) said their lambs' tails were docked level with the vulva -- the recommended length of tails for minimizing fly strike.

Due to the large flock sizes (avg. 2,200) in Australia, the FAMACHA© system is not widely used to make deworming decisions.

Integrated Parasite Management in Sheep Project Benchmark Survey