If lactation occurs in autumn, tender wool will almost certainly result as both the stress of lactation and poor feed quality and limited quantity occur at the same time. Large, usually uneconomic, amounts of supplementary feed may reduce the risk. Consequently, there will be less variation in diameter along fibres, leading to increased staple strength. Weaners Young sheep tend to produce a higher proportion of tender fleeces than adult sheep. This is because they are still growing and body growth is competing strongly with wool growth for the available protein in the diet.
Fibres tend to have a lower minimum diameter in autumn leading to lower strength.
However, during the spring pasture flush in the following year, the weaner's body weight and fibre diameter increase dramatically. This 'blow-out' increases the variation in diameter along fibres and produces tender wool. Neither of these practices is likely to be economical for most growers in Western Australia. Weaners should be run on stubbles in early summer if available, as these are a useful source of unharvested grain. The fibre diameter of wool from heavier animals will still fall towards the break of season but the minimum diameter along fibres will be higher than that from lighter animals.