Natural variation in felting and yarn shrinkage in wool from Romney and Romney-cross sheep

Wool samples from individual Romney and in 1/4Merino 3/4Romney (QM) sheep w ere subjected to a treatment that induced the formation of feltballs, The d iameters of the feltballs were used as a measure of resistance to felting. The Romney samples were also hand spun into short lengths of yam and the pe rcentage shrinkage was measured. Factors affecting loose wool felting and y arn shrinkage were measured. Loose wool feltability was most strongly corre lated with bulk (r = -0.65 and -0.73 for Romney and QM, respectively), crim p frequency (I = -0.53 and -0,41, respectively) and lustre (0.30 and -0.40, respectively). Fibre diameter and staple length were found to play only mi nor roles in loose wool felting and yam shrinkage. In the Romney flock, loose wool feltability was correlated to yarn shrinkag e (r = 0.65), Loose wool bulk and greasy fleece weight were also correlated to yarn shrinkage (r = -0.25 and -0,40, respectively). The greasy fleece w eight relationship is thought to be environmental in origin. Progeny groups sired by various rams were significantly different and accou nted for 6.5% of the variation in loose wool felting (P < 0.10) and 12% in yam shrinkage (P < 0,05), This indicates that selection for decreased yarn shrinkage would induce changes in a flock.