What is Central Test Sire Evaluation?

Central Test Sire Evaluation (CTSE) compares the breeding performance of a sire by evaluating his progeny. Progeny performance is expressed relative to the progeny of other elite CTSE sires.

CTSE has been designed to assess a sire's breeding performance for a large number of traits important to breeders. This therefore assists the selection of sires suitable to a large range of breeding objectives.

CTSE sites located across Australia each have annual matings of between 10 and 16 sires. Sires are mated to an equal allocation of ewes to ensure the difference between the progeny can be attributed to the sire and not the ewes. Approximately 50 ewes of similar breeding to the sires under evaluation are mated to each sire to obtain 25 or more progeny. 15-20 progeny can be expected to provide a satisfactory estimate of a sire's breeding value.

At least one "Link Sire" is mated for each 7 sires entered at a site. A Link Sire is a sire already mated in a CTSE site of that wool type (Medium or Fine), and has 25 progeny at that site that have been evaluated at least once.

Link sires act as the genetic connections between years and sites that allow the direct comparison of all the sires listed within the two groups - Medium and Fine Wool.

The results on this website are derived from a combined site & year sire evaluation analysis, which makes it possible to accurately compare the annual results from a site with those of another site or year. This is because the analysis separates the environment and genetic differences between rams.

Progeny performance is assessed at 10 to 16 months of age (1st) and at 17 to 24 months (2nd). Measured information is collected and measured by an OFFM QA accredited fleece testing operator. Visual assessment is carried out by recognised and independent sheep classers. Processing of the results is carried out independently and reported publicly. All CTSE sites provide their data free of charge to allow the across site measured and visual analysis to be performed and presented on this website.

Site reports provide additional information on traits that are not presented in the combined analysis. Additional traits included in some site reports are fleece rot resistance, internal parasite resistance and the individual conformation and wool quality traits. Site Reports are available on this web site.

Traits not presented and important to a breeder's objective should be considered before using a sire listed on this website.

The CTSE performance of an individual sire in isolation cannot be considered an indication of the performance of the stud which bred the ram.