2006 Media Releases
Thursday, 13 April 2006
AN ELECTRONIC DEVICE TO DETECT SHEEP PARASITES
Meet Seb, a female German Shepherd, trained to detect gastrointestinal nematodes—nasty internal parasites—in sheep.
Her skill, developed by agricultural scientists at La Trobe University, is paving the way for an electronic hand held device to detect sheep parasites that could save the Australian sheep industry millions of dollars a year.
Researchers in La Trobe’s Department of Agricultural Sciences are confident they will have a prototype of the device within five years.
The Head of the Department and Associate Professor, Dr Mark Sandeman, says that gastrointestinal nematodes are responsible for serious production losses for Australian sheep farmers. Many research projects had been undertaken to overcome the problem which has become worse as many parasites have become resistant to drug treatment.
‘We decided on a different approach. Scents, and the use of sniffer dogs to detect them, are used to determine the presences of a number of substances including bladder cancer in humans, accelerants at fire scenes, weeds, drugs, explosives, moth eggs and termites.
‘So we set out to ascertain whether the presence of intestinal parasites in sheep could be detected by their scent,’ Dr Sandeman said.
In early 2005, Dr Sandeman, research student Ms Kate Richards and PhD student Mr Steve Cotton of the University’s Parasite Control Laboratory, obtained two female German Shepherd puppies called Elle and SEB (Scent Experiment B).
With the help of a professional dog trainer, Mr Glenn Williams, they set out to determine whether gastrointestinal nematodes had an odour, whether different species had individual odours, and if so, whether a dog could detect them.
They did this by placing bags of faeces from infected sheep among bags of faeces from healthy sheep. After six months of patient, painstaking training using a response
and rewards method, Seb was able to detect the infected faeces by its odour. Elle failed and was ’voted’ off the project.
With further training, Seb‘s skill increased to the extent that she can detect the presence of infections with between 80 and 90 per cent accuracy.
‘Once Seb had helped us ascertain that the parasites had odours and could be detected by smell, the next step was to isolate the odour molecules of the different parasites,’ said Dr Sandeman.
A PhD student, Ms Jacqueline Burgess, supervised by Dr Sandeman and Dr John Traeger, a Reader in La Trobe’s Department of Chemistry, began working with a mass spectrometer to detect the specific molecules associated with the odour of parasites.
‘This work is proceeding well. We have already isolated odour molecules associated with Telodorsagia, the small brown stomach worm common in sheep in Australia. This worm is very closely related to a worm common in cattle—potentially extending the system to detecting parasites in cattle,’ Dr Sandeman said.
‘If we can find the odour compounds peculiar to the major parasite infections, we could then design an electronic ‘nose’ to detect them. Initially we are planning to design a small hand-held device by which a farmer could check individual animals.
‘It’s a long way off but the detector might ultimately be refined, using biosensor technology and “pervasive” computing—the science of interconnecting “smart devices”—to have sheep checked automatically for parasites.
‘Sheep, which can already be trained to walk over a detector in their paddock once a day to check their weight, could at the same time be scanned automatically for parasites. The ear tag number of any sheep with parasites would be automatically transmitted to the farmer’s computer,’ Dr Sandeman said.
The Australian Sheep Industry Cooperative Research Centre is funding the research.
For further information:
Further information: Dr Mark Sandeman Tel:03 9479 2164 or
La Trobe University Media & Communications Tel: 03 9479 2316