Breeding pays off in flystrike battle


In the midst of WA's tough fly season, Dandaragan producer Peter Wilkinson is confident his sheep will stand up to the test, thanks to a long-term investment in genetics.

With parents Ron and Deanna, Mr Wilkinson operates Challara Merino stud, which first embraced breeding for body and wool types that were less susceptible to flies almost 20 years ago.

"We were seeing a lot of fleece rot on our sheep in the early 1990s and we came to a point with our breeding program where we knew things had to change," Mr Wilkinson said.

Since then they have adopted many of the principles espoused by the SRS Group, and have been breeding plainer-bodied, low-wrinkle sheep and selecting for whiter, denser and freer-growing wools.

The change in body and wool type has resulted in reduced chemical use with applications now limited to timely treatments as the need arises when fly conditions are at their worst.

Such is their confidence in the strategy that the Wilkinsons this year did not mules their lamb drop for the first time.

"We've definitely noticed a reduction in flystrike and fleece rot, especially in our grown sheep, and this change has gone hand in hand with our selection for plainer bodies and whiter wools," Mr Wilkinson said.

The Cooperative Research Centre for Sheep Industry Innovation (Sheep CRC) is providing industry with information on the opportunity to reduce flystrike risk through genetic selection for plainer sheep.

The Sheep CRC has been running a series of producer workshops around Australia to encourage adoption of integrated flystrike strategies, including genetic selection for a plainer body and breech, improved chemical use and timing of animal management.

On-going support and reference information is provided on the FlyBoss website ( ).

Operating as part of the Federal Department of Innovation Industry Science and Research's CRC program, the Sheep CRC is a collaboration of industry, government and the commercial sector. It is working to increase productivity and profitability of the industry through adoption of new technologies in the meat and wool supply chains.

And while breeding and targeted chemical applications have delivered improved protection against flystrike, Mr Wilkinson said flies would always be a challenge which required active management, given the property's location in a 550mm rainfall zone. Most of this falls in winter but any wet and warm spells from August to October can spark a boom in fly populations.

"We find it is really important to monitor the flock closely due to how quickly fly populations can develop here and we then respond by crutching or jetting depending on the time and circumstances," Mr Wilkinson said.

The family runs a stud flock of 750 ewes, plus a further 1750 commercial ewes, and this year sold close to 160 stud rams to its growing clientele. The flock averages 20 microns and 6.5kg fleece weight while the stud ewes averaged 8kg of fleece weight.

"The timing of shearing is also an important factor to consider when managing for flystrike, as long, urine stained, daggy wool will act as an attractant to flies," Mr Wilkinson said.

The main flock at Challara is traditionally shorn in September but shearing will shift to twice yearly from March due to an increase in fleece length since the change in the breeding program.

"In order to continue to increase our standard of breeding we want to source what we think are the best genetics on offer in Australia," he said.

In selecting outside genetics, the Wilkinsons place strong emphasis on the genetic information provided by the Australian Sheep Breeding Values (ASBVs) and will bring in new blood from as far afield as a successful Queensland stud.

The Wilkinsons place particular emphasis on early maturity and worm resistance. By breeding early maturing sheep, they have more commercial marketing options as well as the ability to join ewes at a younger age (provided they are 38kg).

In January and February this year the Wilkinsons joined 700 ewe weaners, all 8-9 months old, from which they were able to mark an extra 500 lambs (71 per cent).

In aiming for improved 'survivability', they look for indications of worm resistance. They have been taking faecal egg counts at Challara for six years and have been downgrading any sheep showing dag - a sign of poor doing and an attractant for flies.

"When we first changed our breeding strategy our production growth stalled a little for a few years before things turned the corner and the new genetics started to kick in," Mr Wilkinson said.

"But in the last two to three years especially our flock performance and productivity has gone to another level and the program is really starting to click on all fronts."


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