SOME of the country's leading southern livestock scientists are convinced managing for flies on unmulesed Merino sheep may not be the burden some growers predict.
Ten months into ceasing mulesing at the eight Sheep CRC Information nucleus flock sites across Australia, the Sheep CRC report a successful management of blowfly strike.
Sheep CRC chief executive Professor James Rowe said a significant amount of data and practical information would come from the work.
"It's early days yet as the project runs through to 2014, though this is the first summer for our initial drop of non-mulesed lambs," Prof Rowe said.
"The flocks contain a range of bloodlines with differing fly strike susceptibility allowing our researchers to identify genetic traits and how heritable they are."
SARDI livestock field coordinator Darryl Smith said the progress of the 220 ten-month-old Merino weaners from 18 Merino bloodlines at South Australia's Turretfiled research centre, was an eye opener with minimal fly problems despite rainy periods and milder weather.
"Seven ewes out of 106 had fly strike, which would be higher than normal but we were collecting dag scores," Mr Smith said.
Lambs at Turretfield, were given a treatment of jetting fluid Extinosad (which claims to prevent blowfly strike in sheep with long wool for up to six weeks without any withholding periods) to marking wounds, an application of Clik when weaned at 5-6 weeks of age, and a crutching for ewes.
"I am confident normal practice, shearing in January with perhaps another crutch in autumn and treatment with Clik post crutching (probably delay 4-6 weeks) would enable stock to get through autumn and subsequent spring."
Mr Smith said crutching had proved challenging on the higher wrinkled sheep.
"Unmulesed sheep can be managed but the amount of trouble and expense will have to depend on the type of sheep run," he said.
Department of Primary Industry senior wool research scientist Dr Ralph Behrandt said no extra treatment had been necessary and little fly strike had been noted in the one-year-old unmulesed commercial sheep at all Victorian DPI centres
"This is in part due to the management regime which has involved using chemical prevention at lamb marking and then shearing of the sheep in January and February," Dr Behrandt said.
"Emphasis is also placed on worm management, using worm egg counts and drenching only when required."
The DPI farm Merinos are primarily Gringegalgona, Merryville cross ewes.
South Australian Merino breeders Phil and Anne Hammat, Baderloo, Spalding, who stopped mulesing their SRS-type 800 stud ewe sheep flock in 2004, said they too were "pleasantly surprised" by the results.
"At weaning at 14 weeks our Merino lambs now weigh up to 50 kilograms with majority over 40kg," Mr Hammat said.
"When mulesing we were lucky to have a lamb strike 40kg. They just don't get that setback."
Mr Hammat said Baderloo ewes cut an average fleece of 7kg of 21 micron wool.
"All sheep are shorn in October and if I think there is a problem I will give light crutch but I have only done this once in addition to normal pre-shear crutch," he said.
The Hammat's applied Clik after heavy summer rain this year but typically have not used.
"The main thing is to get the wrinkle off. I am not convinced about bare breech as I noticed any ewes with bare breech from vulva to udder usually get a channel of dags form on them," Mr Hammat said.
A survey of fly strike management by Australian Wool Innovation found 32 per cent of all lambs born in Australia this year would remain un-mulesed.