Making More from Sheep Australian Wool Innovation Limited Meat & Livestock Australia
MODULE 9: Gain from Genetics
Procedure 9.1
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Genetic decisions have long-term impacts on your flock. Take a longer term view of the market when planning your flock structure and production targets. Considerations include the opportunities for premiums or adding to the relative value of wool and meat. These considerations need to be part of a 10-year time frame as it can easily take 7-10 years to see change in your flock.



At a Glance
pt Identify the most profitable traits for your enterprise

pt Quantify current productivity levels to identify opportunities for gain

Key decisions, critical actions and benchmarks

In general, the more traits you select, the slower the rate of progress on each trait. Therefore it is important to identify those traits that are most important in your business. This involves:

  • Determining target markets (see procedure 2.1 in Market Focused Wool Production and procedure 3.1 in Market Focused Lamb and Sheepmeat Production). This is likely to include consideration of:
  • Fibre diameter, staple length and staple strength
    • Lamb markets (export, domestic or finisher)
    • Breeding ewe replacements.
    • Using feedback from your wool, lamb and sheep sales to evaluate performance.
  • Objectively quantify your flock’s current productivity, eg, kilograms of wool or liveweight of lamb or surplus sheep per hectare to highlight what might be genetic limitations or a mismatch between your current genetics and your market opportunities.
  • Participating in formal or informal benchmarking programs to identify the strengths and weaknesses in your enterprise and align your breeding objectives accordingly (see procedure 1.3 in Plan for Success).
  • Designing the breeding program to meet production targets and fit physical production capability. This involves consideration of the:
    • Breeding system: straight-bred Merino or dual-purpose maternal breeds? Composite maternal flock, first- or second-cross prime lambs?
    • Design of your breeding program to account for your on-farm resources, eg, consider the number of replacement ewes required annually.

The Australian Sheep Industry Cooperative Research Centre (Sheep CRC) has developed tools to help answer these questions, including:

  • Tool 9.1 : a ‘wether calculator’ to help determine the economic consequences of varying the portion of wethers in a Merino flock, and
  • Tool 9.2 : a ‘Merino versus terminal sire flock’ model to help assess the balance of self-replacing Merino and terminal sire matings.

Identify key traits essential for achieving production targets. In this module a ‘trait’ is defined as a production characteristic that you may select for, eg, fibre diameter, fleece weight, growth rate, eye muscle depth or number of lambs weaned (see tool 9.3 for sheep breeding value definitions).

The traits to identify, and relative importance may include:

  • Reproduction: weaning rate, mothering ability
  • Growth traits: weaning, post weaning, yearling or adult weight
  • Fleece traits: fibre diameter, fleece weight, staple strength, staple length
  • Carcase traits: fat and eye muscle depth, yield
  • Disease resistance: worms, footrot.

Table 9.1 illustrates the relative importance of the key traits for a range of enterprises. For example, a medium wool Merino producer may want to maintain fibre diameter while increasing fleece weight, growth rate, reproduction rate and worm resistance. Note that the key traits and their relative importance will vary regionally and between businesses.

Feedback from wool and lamb sales will help sheep producers prioritise the traits to focus on. However, when interpreting market feedback remember:

a) To take a longer-term view of the market, and

b) That flock genetics is only one contributing factor.

Table 9.1: Example of relative emphasis of traits when selecting rams for a range of enterprises
( = High, = Moderate, = Low)

  1. Includes characteristics such as fibre diameter, staple strength, crimp, style.
  2. May vary noticeably across regions.


Fine Merino

Medium Merino

Strong Merino

Maternal – self replacing

Maternal – 1st cross


Wool quality1

Fleece weight (kg)

Growth rate (g/head/day)

Carcase attributes
Fat & eye muscle depth

Worm resistance2
Worm egg count

Lambs weaned

Fleece rot resistance

Structural soundness


Signposts Signposts


The Sheep CRC: technology, tools and know-how to assist the sheep industry to deliver, in a profitable and sustainable manner, products highly desired by domestic and export customers.Visit the Sheep CRC section of the Livestock Library at: and search by subject.

Maternal Central Progeny Test: compares the merit of maternal sires where it counts - their ability to produce crossbred lambs and ewes that have superior production and are efficient and profitable for the sheep producer. For a summary of the findings visit:, or download the full report here. (1.2MB)

Selection Demonstration Flocks - what we have learnt: for a paper summarizing the lessons from the South Australian selection demonstration flock go to: 

Breeding and Selection: This section of the NSW DPI website provides a range of breeding and selection resources for both sheep meat and wool. Visit:

Sheep Selection Tools: This AWI publication provides a summary of a wide range of industry tools available to woolgrowers to help achieve their breeding goals. Order a printed copy by calling the AWI Helpline on 1800 070 099, or download a copy (0.8MB)

For a range of sheep genetics information visit: