The Scent of worms: first steps to a machine to smell parasites in sheep poo

Doctoral student Jacqueline Burgess from La Trobe University has identified odour molecules associated with the small brown stomach worm.

It’s a step closer to creating an automatic “worm sniffer” in her project to determine whether the odour of sheep faeces changes when an animal is infected with dangerous parasitic worms in the digestive system such as the small brown stomach worm, barbers pole worm or the black scour worm.

Intestinal worms are a large financial burden to the livestock industry in Australia, causing production losses and animal death across the country.

This work has been encouraged by the previous success of ‘Seb’, the German Shepherd sniffer dog, trained at La Trobe to detect parasite infected sheep poo.

This, together with the development of new systems for odour detection and a need for rapid diagnostic techniques has lead researchers to ask the question, ‘what compounds might the dog smelling?’ and ‘can we design a device to detect these odours?’

The project replaces the use of a sniffer dog with a gas chromatograph, coupled to a mass spectrometer, identifying specific molecules associated with the odour of faeces infected with parasites. Already, odour molecules associated with the small brown stomach worm have been identified using this equipment, and research is now underway to identify compounds linked with the odour of barbers pole and black scour worms.

The identification of specific odours associated with the presence of these parasites, will enable the researchers to design an electronic ‘nose’ device to detect them. A detector may ultimately be refined using biosensor technology, to have sheep checked automatically for worms.

Detectors may one day be integrated with Australian Sheep Industry CRC developed, automatic weighing and monitoring systems. The electronic tag number of a sheep with parasites would be transmitted to the farmers’ computer.

Although this idea is a long term goal, the research is progressing well, and researchers are confident they will have a prototype of at least a poo sniffing device within five years.

If a producer could identify the individuals that require treatment, from those that don’t, the costs and labour associated with maintaining a healthy flock of sheep would be reduced considerably.

Research is being undertaken with the financial aid of the Australian Sheep Industry CRC and under the supervision of Dr Mark Sandeman in the Department of Agricultural Sciences and Dr John Traeger of the Department of Chemistry at La Trobe University.

Jacqueline Burgess is one of 16 early-career scientists presenting their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Federal and Victorian Governments.

Images

Jacqui Burgess from LaTrobe University collecting samples from her sheep.Credit: Stephen Cotton Jacqui Burgess isolating odour molecules using a gas chromatograph at LaTrobe University.Credit: Stephen Cotton
Jacqui Burgess from LaTrobe University collecting samples from her sheep.Credit: Stephen Cotton Sheep dropping used for odour sampling.Credit: Stephen Cotton

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