Fibre diameter and wool growth efficiency estimated from WA wether trials.

The WA linked wether trial dataset contains records on 7500 animals born in the five years 1997 to 2001 and sampled from 303 flocks. These animals were monitored for fibre diameter, clean fleece weight and live weight over two years in 24 trials. The aim was to compare the genetic productivity of the flocks. Inclusion of a link team in each trial enabled comparison between trials. The estimate of efficiency of wool growth used was the fleece weight index (grams of clean wool production per unit of live weight near shearing). Values recorded varied between 34 and 115 g/kg, with a small positive relationship (r = 0.08) with fibre diameter. It is concluded that for half the flocks of WA sheep producers there is a significant opportunity to improve wool growth efficiency by use of animals from genetically superior flocks, with no need to change their current fibre diameter.