DNA test to revolutionise sheep worm control

Jun 23, 2008
DNA test to revolutionise sheep worm control
The tail ends of Barber's pole worm adult females taken from one sheep infected with a single isolate of this worm species.

CSIRO scientists have moved a step closer to developing a novel DNA test which has the potential to revolutionise management of one of the biggest threats to sheep health in Australia, the barber’s pole worm.

Barber’s pole worm, Haemonchus contortus, is one of the top three nematode parasites of sheep. Nematode parasites cost the Australian industry hundreds of millions of dollars each year in lost production, veterinary drugs, and animal deaths.

The discovery of DNA markers by CSIRO Livestock Industries researchers working at Armidale, NSW, will allow producers in the future to implement control strategies that specifically target the worm strains present on their own properties.

Targeted control has the potential to reduce the impact of worm resistance to veterinary drugs, reduce drug usage and lead to better health and welfare outcomes for sheep.

CSIRO Livestock Industries’ research scientist, Dr Peter Hunt, said new work just published in the International Journal for Parasitology is the first to report on the effects of divergent barber’s pole worm strains on sheep and link these effects to DNA analysis.

“Our work has revealed for the first time that different strains of barber’s pole worm can have dramatically differing effects on their hosts,” Dr Hunt said. “One strain caused a 30 per cent reduction in wool growth while another had little impact. In another example, one strain caused a 38 per cent reduction in red blood cell numbers, while the most benign strain resulted in only a 14 per cent reduction.

“We have found ways to identify these different strains of worms via their DNA, so that with a simple test, a producer could determine which strain is present and therefore what to do about it. At the moment, if faecal counts show animals are infected, the main management option is for producers to drench their sheep,” he said.

“We also hope that DNA markers can be used to track changes in worm populations on individual properties and link these with management decisions. When enough graziers became involved, correlations between individual markers, parasite management strategies and worm characteristics should emerge.

“The process should work similarly to successful genetic databases such as Breedplan, but more work to develop good DNA markers is needed for this outcome to be realised.”

Dr Hunt said that while this research would trigger a new outlook on sheep management, in the short-term it increased the importance of on-farm quarantine.

“We have known for some time that there is a risk of bringing drug resistant worms onto a property when new stock are introduced, but now we know the stakes are even higher,” he said.

Source: CSIRO

Explore further: Best of Last Week - Zero friction quantum engine, twisted radio beams and Ebola outbreak update

add to favorites email to friend print save as pdf

Related Stories

Young smooth snakes rely on reptiles

Aug 11, 2014

A new way of using DNA analysis to find out what reptiles have been eating has revealed that the UK's rarest snake species may be under pressure because it needs very different kinds of food at different ...

Norway's quest to discover all of its native species

Dec 19, 2013

More than a thousand new species –nearly one-quarter of which are new to science – have been discovered in Norway since a unique effort to find and name all of the country's species began in 2009.

A skeleton for chromosomes

Aug 26, 2013

Researchers at the IMP Vienna discovered that cohesin stabilizes DNA. Jan-Michael Peters and his team at the Research Institute of Molecular Pathology (IMP) found that the structure of Chromosomes is supported ...

Explainer: What are stem cells?

May 20, 2013

In a paper published in Cell yesterday, scientists from the US and Thailand have, for the first time, successfully produced embryonic stem cells from human skin cells. ...

Recommended for you

Ig Nobel winner: Using pork to stop nosebleeds

Sep 19, 2014

There's some truth to the effectiveness of folk remedies and old wives' tales when it comes to serious medical issues, according to findings by a team from Detroit Medical Center.

History books spark latest Texas classroom battle

Sep 16, 2014

As Texas mulls new history textbooks for its 5-plus million public school students, some academics are decrying lessons they say exaggerate the influence of Christian values on America's Founding Fathers.

Flatow, 'Science Friday' settle claims over grant

Sep 16, 2014

Federal prosecutors say radio host Ira Flatow and his "Science Friday" show that airs on many National Public Radio stations have settled civil claims that they misused money from a nearly $1 million federal ...

User comments : 0