Comparison of fibre diameters measured in the skin and wool of Merino sheep

Abstract

This study was undertaken to determine if there is a relationship between the fibre diameter measurement obtained from a skin section and that obtained from the corresponding wool fibres. A skin biopsy (1 cm diam.) was taken from the undipped midside of 29 fme-woolled Merino sheep, under local anaesthetic. The fibres protruding from the biopsy were severed at the skin surface and fibre diameter measurements determined at intervals along their length. Fibre diameter was also measured in the skin sections prepared from the biopsies. The fibre diameter (mean ± SEM) from the skin sections (15.0 + 0.2 urn) was significantly lower (P < 0.001) than the mean wool fibre diameter (19.2 ± 0.2 µm). Fibre diameters measured along the fibre bundles were highly correlated (0.81-0.88), whereas the correlations between fibre diameter from skin sections and wool were much lower (0.64). The lower fibre diameter obtained from skin sections is likely to result from the effect of sample preparation, though the effect of nutrition can not be dismissed. The results of this study indicate that fibre diameter obtained from skin sections can not be used to reflect fibre diameter of wool with a high degree of accuracy.