Programs designed to remove the need for mulesing:

3. Genetic research and enhanced breeding for flystrike resistance

>> Back to the flystrike prevention menu

Recent results from genetic research trials indicate there are good prospects for reducing the incidence of flystrike, however this is likely to be a long-term solution.

The breeding cycle (average generation interval) for Merino sheep is three to three-and- a-half years, which limits the speed with which advances appear. Breeding must also take into account other traits so that there are no adverse effects on sheep productivity, health and welfare.

Genetic research to identify sheep with high natural resistance to flystrike is underway across Australia at several sites to take into account different sheep types and environments.

These trials indicate that different factors affect sheep differently in different environments. Sheep that are most at risk of flystrike have higher degrees of skin wrinkle and/or wool cover in the breech region and/or are more susceptible to dag accumulation and urine staining of wool.

The newsletters from the trials contain further information on the results from the trials.

• CSIRO Armidale Newsletter Issue 1 - November 2007 ( 291Kb PDF)
• CSIRO Armidale Newsletter Issue 2 - August 2008 (211Kb PDF)
• CSIRO Armidale Newsletter Issue 3 - April 2009 (543Kb PDF)
• DAFWA BSR Newsletter Issue 1 - September 2007 (286Kb PDF)
• DAFWA BSR Newsletter Issue 2 - July 2007 (234Kb PDF)
• DAFWA BSR Newsletter Issue 3 - September 2009 (305Kb PDF)

Click here to read more publications related to breeding.

This body of work has enabled the development of breech trait scoring charts, which farmers can use to select their sheep to have higher natural resistance to flystrike. These values provide a consistent language for farmers to use when scoring sheep across the country. The charts are available by calling the AWI Helpline on 1800 070 099.

Building on this development, standardised Sheep Breeding Values (across-flock genetic benchmarks) for the breech wrinkle traits have been released. They are a tool for sheep and stud breeders to identify sires that have traits associated with enhanced natural resistance to flystrike. They have been developed from 32,000 individual sheep records in the Australian National Merino Genetic Database. Download the Visual Sheep Scores pocket guide in PDF format (4.98 Mb).

There is already widespread adoption of breeding strategies by stud breeding operations and commercial woolgrowers across Australia. There are also now widespread education and extension programmes to assist farmers adopt selection and breeding programmes, and to manage their sheep without mulesing, where-ever this can be safely achieved without increased flystrike risk. See Non Mulesing Network newsletters on DAFWA website.

The availability and use of these new breeding tools and extension programmes will enable the industry to accelerate the rate of progress toward naturally resistant sheep types, by allowing efficient identification of breeding stock with high levels of natural resistance to flystrike.

Given the varied environmental effects on the incidence of breech and body flystrike, there is no one-size-fits-all breeding program.

The implication is that individual farms will need to develop customised strategies, which target the key environmental challenges and genetic mechanisms applicable to their flock.

Download the following presentations on research into breeding for breech strike resistance.

• Breeding Sheep for Breech Strike Resistance July 2009 - Part A (1.6Mb PDF)
• Breeding Sheep for Breech Strike Resistance July 2009 - Part B (224Kb PDF)
• Breeding Sheep for Breech Strike Resistance April 2010 (408Kb PDF)
• Feasibility of Breeding for decreased Breechstrike for Merinos DAFWA Mt Barker WA - June 2009 (128Kb PDF)