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Help on sire performance figures

Australian Sheep Breeding Values

Merino Superior Sires now uses the sheep industry's common language for describing breeding values. This means that sire performance figures for individual traits are Australian Sheep Breeding Values (ASBVs), produced by Sheep Genetics Australia

MSS sire evaluation data has been complimented with data from individually recorded Merino flocks. As such MSS sires are now directly comparable with Merino animals reported in SGA.

On this web site ASBVs are reported for each measured trait. As each sire (or dam) only passes their genes to their progeny, the difference in progeny for a particular trait will be the value of the ASBV.

Web Search ASBVs Regularly Updated

ASBVs in the web search function are updated every 2 weeks when the SGA analysis is rerun. The date located at the top of the web search table indicates which run the ASBVs have been derived from.

What does this mean for you? There will be subtle differences between ASBVs in the printed version of Merino Superior Sires 12 (or PDF downloadable version) compared to the web search. Sires that have only been entered into Sire Evaluation will have very similar performance in the web search and hard copy.


Each ASBV is reported with an accuracy figure. This percentage figure indicates how well you can rely on the information provided. Something extremely accurate has a value close to 100%.

Traits have different reporting thresholds for accuracy. This is strongly influenced by the heritability of the trait. ASBVs are reported when the accuracies are higher than the following thresholds for the traits listed:

HFD 60%


The indexes reported for MSS are the same as those available through SGA, and are built by combining ASBVs. Each trait in the index is given a level of emphasis determined by its importance in the breeding objective. Because breeding objectives are not the same for all producers, different indexes are available. MSS presents a wide range of indexes to cover the majority of Merino enterprises.

The three indexes used in the main report table are:

  • Dual Purpose 7% (DP7): Moderate reduction in fibre diameter and gain in fleece weight. High body weight and reproduction rate gain, and maintain staple strength.
  • Merino 14% +SS (M14+SS): Large fibre diameter reduction and moderate gain in body weight. Maintain fleece weight, reproduction rate and staple strength.
  • Fine 10% +SS (F10+SS): Moderate reduction in fibre diameter and gain in fleece weight and staple strength. Low gain in body weight and maintain reproduction rate.

Indexes are reported with A and R codes. A means that a sire is linked for all traits in the index except reproduction, while R means a sire is linked for reproduction traits.

Using the sire query system

  • The main heading of the sire performance table shows the date when the ASBVs were obtained from SGA.
  • ASBVs are shown for 20 sires at a time. The defult sort in the table is alphabetically by sire name.
  • View the next 20 sires, using the Pages links at the top and bottom of the table (these look like highlighted numbers).
  • To sort on other traits or indexes, simply click on the appropriate table heading. This enables you to find trait leaders.
  • Change traits displayed using the Choose traits link.
  • View accuracies by clicking the Show accuracies link at the top of the table (turn them off by clicking Hide accuracies).
  • Rank sires using your own index, with the Define custom $index link.
  • Hold your mouse over the sire name to view summary information about the sire.
  • Click on the sire name to view detailed information.