Wool Genetics

Many characteristics associated with wool are highly or moderately heritable, allowing breeders to make genetic improvements through selection.

The most important wool traits are already available as Australian Sheep Breeding Values from studs who are members of MERINOSELECT.

ASBVs for some other wool traits are in development by Sheep Genetics using data collected over many years from Central Test Sire Evaluations, research flocks (in particular the Sheep CRC Information Nucleus), and industry flocks.

Commercial breeders can take advantage of ASBVs when selecting rams from studs offering this information. More information on using ASBVs. Some commercial producers accelerate genetic gain in their flock by measuring the key traits, fibre diameter and greasy fleece weight, on their yearling or hogget ewes and selecting the finer and/or heavier cutting ewes as replacements.

Most breeders will apply some visual assessment to wool traits when they are classing ewes. A Visual Sheep Scores guide is available to assist people in scoring particular traits.

Table 1: Heritabilities of wool traits at yearling age

Some traits are correlated with other wool, meat or sheep traits, that is there is a tendency for a change in one trait to result in a change in the other trait. Some correlations are favourable, for example, a sheep with bigger body weight tends to have a bigger fleece weight. Other correlations are unfavourable, the most notable being higher fleece weights are generally related to broader wool, rather than more valuable fine wool. Regardless, significant genetic improvement making fleeces both finer and heavier is being achieved by studs. As the correlation is not 100% there are animals that have both a fine and a heavy fleece, and these are selected for breeding. The same logic can be applied to other traits where their correlation is unfavourable. ASBVs can be used to identify the performance of a ram for specific traits, allowing buyers to identify superior animals, regardless of correlations.

To find out more about Genetics click here.

Choose from the tabs below to find more detailed information.