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Answers for the Q&A Webinar- 'Ewe Turn- Using Genetics to Tackle Flystrike'

Posted by Bestprac on Nov 05 2013

On Thursday October 31, Bestprac coordinated a webinar to discuss the features of the recently released case study, ‘Ewe Turn- Using Genetics to Tackle Flystrike.’ Bestprac has made available the link to watch the webinar as well a full report of the questions and answers.

Geoff Lindon, Australian Wool Innovations Program Manager for Productivity and Animal Welfare, was online to provide an overview of the main features of the case study, as well as insight into Australian Wool Innovations position on tackling flystrike.

This was followed by a question and answer session with Geoff, where participants could have their questions answered. Below are the participants questions which have been answered by Geoff. Click here to view the recording of the webinar.

1. The case study has reduced micron from 22.8 to 18.6, which seems amazing since micron was not stated as a key objective.

This micron reduction has occurred through the introduction of new management practices and outside sires over 20 years. In this flock, the Australian Sheep Breeding Value (ASBV) for Yearling Fibre Diameter (YFD) has fallen by 1 over the last 8 years.

 Actual flock microns are the result of genetics interacting with many environmental factors, including;

  • country
  • seasonal conditions
  • management (they are now joining ewes at 8 months rather than 18 months)
  • and fertility rates that have increased by 20%

There are other studs in Western Australia with a YFD ASBV of -0.5 that have average microns between 18.5 and 19.5 microns.

2. Do you know approximately how many (or percentage of) Australian wool producers are using genetics to reduce wrinkle?

Nearly all wool producers are using genetics to reduce wrinkle. Over the last 20 years, there has been a reduction in wrinkle due to a range of reasons, the rise of prime lamb and mutton prices relative to wool, skin values and risk of breech strike. Australian Sheep Breeding Values (ASBVs) for breech wrinkle have only been available since late 2009.

3. At this stage, what is the approximate success rate of achieving cessation of mulesing?

The ‘Moojepin’ Case Study points out the importance to plan the cessation of mulesing and the need to get the sheep ‘right’ first before ceasing to mules.

The feasibility of breeders to cease mulesing depends on many factors, such how wrinkly the sheep are to start with, sheep type and, very importantly, the risk of dag and urine stain.

Dag is the most important risk factor for breech strike but the existence of dags varies enormously between improved annual, perennial and native pastures; and between regions and districts. There are some wool growing areas where there are few dags (low rainfall and summer rainfall regions) and other areas where there are large amounts of dags (high rainfall and winter dominant regions).

4. Are there any sectors within the wool market where there are premiums for wool from un-mulesed sheep?

A review of the Australian wool market in the 3 years 2008/09, 09/10 and 10//11 shows a premium of 1.6 percent for unmulesed wool. Producers also have the option to sell non-mulesed wool direct to market, where there can be reasonable premiums but there is limited objective evidence of the size of the premium.

5. Has there been any economic analysis of the costs and benefits of the strategy, as outlined in the case study?

Other than the detailed statistics provided for the case study and their significant financial impact, there has not been a formal economic analysis. ‘Moojepin’ is a ram breeding enterprise and thus its financial performance is heavily impacted by its ram sale clearance and average ram price. These are not relevant to commercial enterprises. The trait trend graphs in the case study show clear movement in the key economic traits and, as David outlines, further progress is being targeted.

6. Moojepin has significantly decreased Yearling Clean Fleece Weight (YCFW) from +20% to +5% whilst increasing Number of Lambs Weaned (NLW) from +2% to +3% and carcass traits by only relative modest amounts. How do the economics stack up?

As always, actual production (phenotype) is the result of the interaction between the genetics and the whole environment in which animals graze. Small genetic improvements can lead to large changes in actual phenotype under most situations.

Lambing % has gone up by 20-25%, which includes now joining at 8 months of age, wool value has held with the micron reduction making up for lower cut and higher fleece weights are now being targeted, growth has increased, the age of turn off decreased and muscle is up.

7. Is there definite correlation between the decrease of body wrinkle and the increase of fertility?

There have been many trials in this area. The overwhelming assessment is that lower wrinkle leads to higher fertility, although not in every trial. Studs that place a large emphasis on fertility and little on wrinkle can still have highly fertile sheep but, generally speaking, the ‘plainest sheep’ have the ‘higher fertility’.

8a. How are sniffer dogs implemented into commercial practice?

Sniffer dogs (and very preliminary gas chromatography work) were used as a tool to assess the risks  when making a decision regarding a large investment into a 3 year breech odour project. The outcomes of both were encouraging and the investment into the odour project has commenced.

At this stage, it is not envisaged that the sniffer dogs will be used commercially but this could change. An ‘electronic nose’ may be an option depending on the outcomes of the research.

8b. What is the investment required to implement this strategy? Do you have any information on this?

We need to complete the Research and Development first.

9. Does reduction in wrinkle always result in reduced fleece weight, and if so what average percentage?

The correlation between lower wrinkle and lower fleece weight is +0.3 which is defined as moderately positive. However, if a correlation is only 0.3, there are still reasonable numbers of animals that have a wide mix of the traits, i.e. numbers of animals that are both low wrinkle and high fleece weight and also animals that are high wrinkle and low fleece weight.

The correlation does mean that the traits need to be managed well to achieve lower wrinkle and higher fleece weights, as ram breeders have achieved, with a similar correlation of +0.3 between fibre diameter and fleece weight.

Can you please explain the traits that make up a subjective measurement of style?

The term ‘Style’ is a term that can mean different things between breeders across the country.

I refer to the ‘Economic Value of Fleece Wool Attributes’ by Liz Nolan Sydney University 2012 page 35, on the AWI website.

  Style Density Character (Crimp Definition) Length Regularity Tip Type Visual Colour Visual Dust Penertation of Staple
1 Choice Dense Excellent Excellent Square Extra white Nil
2 Superior Dense Very Good Excellent Square Very White Minimal
3 Spinner Dense Good Good Square White Light
4 Best Good Good Good Square, some tippiness White, Some cream LIght (5-10%)
5 Good Good, Some Thinness Good, Fair Some variation All Good Creamy Unscourable Light Medium (8-25%)
6 Average Increasing thinness Good, Fair, Poor Some variation All Good Creamy Unscourable Heavy (25-60%+)
7 Inferior Thin Wasty Open Good, Fair, Poor Some variation All Good Creamy Unscourable Heavy (60%+)

 

Do we know how long it takes David to mother up 2500 ewes at lambing and how he does this?

The time taken to manually mother up lambs immediately post lambing can vary according to the yard layout and the number of mobs and total number of lambs. Normally it would take 3 to 5 days with 3 people. 

Where birth weights are required, daily lambing rounds much be undertaken and the time required, again, depends on many issues such as on the length of the lambing period, paddock layout, number of lambs etc.

Go to the case study

Last changed: Nov 06 2013

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