Breeding plain-bodied fine wools - no problem

Fine wool producers are now seeking to breed “easy care” plainer-bodied animals which would be less susceptible to flystrike.

However, until now there has been no genetic information available on the consequences of selecting for reduced wrinkle in fine wool bloodlines, as most previous research was undertaken with medium to broad wools from the 1950s to 1970s.

NSW DPI senior research scientist, Dr Sue Hatcher, has recently completed an analysis of the genetic relationships between wrinkle score and a wide range of wool production and quality traits on a mixed bloodline flock comprising fine wool wethers.

Her results clearly demonstrate variation in wrinkle score accounts for more than 90 per cent of the total variation in these traits, between and within animals.

In addition, wrinkle scores in fine wools were both highly repeatable and highly heritable.

“These results indicate that wrinkle scores in fine wool sheep are under a similar degree of genetic control as fibre diameter and clean fleece weight,” Dr Hatcher said.

In agreement with previous work using broader bloodlines, correlations between neck and body wrinkle were strong and positive.

This indicates either score will provide a reliable visual description of the degree and quantity of wrinkles on an individual animal.

“Fine wool producers looking to breed plainer-bodied animals can select for reduced wrinkle without any major detrimental effect on the wool production and quality of their flock,” Dr Hatcher said.

“In fact, selection for reduced wrinkle will actually lead to denser fleeces with a softer handle.”

However, greasy and clean fleece weight both had economically unfavourable relationships with wrinkle.

“But the good news is that this unfavourable relationship is similar in magnitude to that occurring between clean fleece weight and fibre diameter and experience has shown us simultaneous improvement in these two traits is achievable,” Dr Hatcher explained.

“So fine wool producers can include wrinkle score in their selection index and reduce wrinkle score while maintaining or even increasing fleece weight.”

Selection for plain-bodied fine wool sheep would have a positive impact on wool quality.

Dr Hatcher said plainer-bodied fine wools would tend to produce finer, higher yielding fleeces with longer staple length, lower variation in fibre diameter, improved resistance to compression and measure colour.

“Liveweight was only weakly correlated with wrinkle, indicating that selection for plain-bodied fine wools will not affect carcass weight.”