Program manager: Dr Norm Adams, CSIRO Division of Animal Production, Floreat Park, WA
This program aimed to reduce the incidence of tender and weak wool in the Australian wool clip. Staple strength is second only to fibre diameter in determining the relative value of raw wool because it is an important contributor to hauteur, which is the fibre length in the wool top after early stage processing. Low staple strength is a problem in Australia where sheep graze in the many areas with dramatic seasonal fluctuations in pasture quality and quantity.
The weakest point in a staple (position of break) often coincides with the change in feed supply at the break of the season. However, there are a number of other factors that contribute to the strength of the wool. The amount and timing of supplements fed during summer, exposure to summer rainfall, weaning procedures and reproductive stress may all contribute. In addition to these environmental factors, there are differences in staple strength that are related to the age and the genotype of the sheep. These anomalies indicate a complex problem.
We addressed these problems in a coordinated program of studies on-farm and in the animal house together with complementary activities in wool processing to improve the value of the wool.