Science has gone some way to finding alternatives
to mulesing.
Image courtesy of iStockphoto

Now here is a sheep tale that started in 1929 when South Australian Merino breeder John Mules cut away the fly-infested breech of one of his top ewes. Ouch.

His act of mercy, which has been modified and improved over nearly 80 years of breeding, has developed into the mulesing practices now under attack by animal welfare groups concerned over the pain and suffering of sheep flocks in Australia.

Without mulesing, flystrike would kill an estimated three million sheep in those years when climatic conditions favoured fly breeding.

In the face of growing public discontent and the demand for science to find a solution, Australian wool producers have set a deadline of 2010 to find new and cost-effective ways to avoid surgical mulesing.

Mulesing involves cutting skin and wool from the sheep breech or behind to protect against flystrike. Removing the skin reduces the risk of contamination by urine and faeces, making the area less attractive to flies.

Recently, a survey of 1410 sheep producers found 32 per cent of all lambs born in Australia in 2008 were not mulesed; 11.5 per cent of the Australian wool clip was sourced from non-mulesed sheep; and 14.8 per cent of producers had a breeding strategy based on sourcing bare-breeched rams.

Mark Dolling, Department of Agriculture and Food WA director of animal industries development, said having nearly 15 per cent of survey respondents focusing on alternatives to mulesing was encouraging.

But is it enough to meet the 2010 deadline, which was set in 2004?

Many farmers at that time did not act immediately, believing the "alternatives" could simply be bought off the shelf sometime in the next six years.

"The first alternative to mulesing is to simply stop doing it, and maybe using more chemicals," Dr Dolling told ScienceNetwork WA. "Good management that uses chemicals as a back-up can also be effective."

Attacking the fly itself by baiting or breeding sheep when fly numbers are down could form part of management programs aimed at protecting livestock from infection, and death.

Dr Dolling said longer term approaches involved selectively breeding sheep for flystrike resistance, which WA scientists are testing in Mt Barker flocks.

Dr Dolling recalls taking on the flystrike problem in sheep about 15 years when he was involved in a research project, partly funded by the late Kerry Parker, in which sheep behinds were frozen and exposed to radiation.

Though effective, the scientists learnt more about the regenerative nature of wool follicles than they did finding a solution that stuck.

The CSIRO has been investigating alternatives to mulesing since the mid-1980s. Early studies involved using chemicals to remove wool from the breech. Welfare concerns led to studies investigating the potential of a photoactive chemical already present in the body to prevent wool follicles growing inside the skin.

University of Adelaide researchers later identified a protein that kills wool follicles in a way similar to CSIRO's photoactive chemical, but while it found a way of delivering the protein into the sheep's body, the protein was dropped in favour of a compound used in the treatment of varicose veins in humans.

Another non-surgical alternative is a biodegradable plastic clip which acts in a way similar to rubber rings used to castrate lambs.

Dr Dolling added that for post-mulesing pain relief, the anaesthetic spray trisolfen was also available to farmers in Australia.

The new methods will go some way to appeasing animal rights groups such as PETA (People for the Ethical Treatment of Animals) which is lobbying against the use and sale of Australian wool sourced from mulesed sheep.

PETA wants farmers to immediately end clip-mulesing in favour of "humane flystrike control methods" that did not involve removal of sheep skin or flesh.