De-odourising sheep makes them less appealing to blowflies

A global research project involving the collaboration of an ARC-supported researcher at The University of Western Australia (UWA) with Dr Johan Greeff at the Department of Primary Industries and Regional Development Western Australia, has identified compounds in Merino sheep wool that are attractive to Australian blowflies.

The discovery could help breeders develop fly-resistant flocks of sheep, which will improve animal welfare and productivity.

The research team, which included ARC Discovery Early Career Researcher Award (DECRA) recipient at UWA, Dr Bjorn Bohman, says that the findings could help to prevent flystrike, a distressing disease caused by blowflies, which poses a significant health risk to sheep and which has been estimated to cost the agriculture industry $280 million annually.

The researchers say that identifying the compounds which attract flies, octanal and nonanal, is a step towards the development of approaches for preventing flystrike that are more clean, green and ethical in that they avoid the use of insecticides and mulesing.

The research was supported by Australian Wool Innovation Ltd and was undertaken as a part of the PhD studies of Dr Guanjie Yan, who was working at UWA with the support of the China Scholarships Council. Dr Yan established a technique for studying the sense of smell in flies and was able to show that blowflies react to individual odour compounds that are heritable in Merino sheep. This work now needs to be expanded to demonstrate whether it could lead to a more effective way to breed sheep that are resistant to flystrike.

	The study showed that merino sheep clearly have individual differences in the chemical content of their wool—the fly-attractive wool contains volatile compounds not found in non-attractive wool.

 

Images of Merino sheep used in the trial. Credit: UWA.