Saturday, July 19, 2008

Novel DNA test for worm control

CSIRO* scientists have moved a step closer to developing a novel DNA test which has the potential to revolutionize management of one of the biggest threats to sheep health in Australia (and the U.S.) -- the barber pole worm.

single strain of barber pole worm (image by CSIRO)The barber pole worm, Haemonchus contortus, is one of the top three nematode parasites of sheep and goats. It is the primary internal parasite affecting sheep and goats in warm, moist climates.

Nematode parasites cost the Australian and American industries hundreds of millions of dollars each year in lost production, veterinary drugs, and animal deaths.

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 pole worm strains on sheep and link these effects to DNA analysis.

The research showed that one strain of the barber pole worm 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.

Dr. Hunt said that while this research would trigger a new outlook on sheep management, in the short-term, it increases the importance of on-farm quarantine to reduce the risk of bringing drug-resistant worms to a farm.

*CSIRO - Commonwealth Scientific and Industrial Research Organisation in Australia

Read CSIRO media release