Implications to fleece evaluation derived from sources of variation contributing to cashmere fibre curvature

Abstract

Cashmere fibre curvature (crimp) has important impact on the softness and quality of cashmere textiles, the efficiency of cashmere processing and cashmere production. This work was aimed to quantify the magnitude and direction of factors affecting cashmere fibre curvature, with data collected from 11 Australian commercial cashmere farms, using general linear model analysis. Nineteen parameters were recorded for 1244 goats. Following log transformation the best model for fibre curvature included farm, age, clean washing yield, mean fibre diameter, cashmere yield, fibre diameter standard deviation, and live weight and the interactions between these terms. The percentage variance accounted for was 71.7%. Mean fibre diameter alone accounted for 39% of the variation in fibre curvature and farm accounted for 49% of the variation. Cumulatively mean fibre diameter and farm accounted for 66.6% of the variation existing in fibre curvature. For the other terms, age added 2.2% and the other fibre measurements a further 2.9% to variation accounted for by the best model. Results suggest that within a farm, using cashmere fibre crimp frequency to estimate mean fibre diameter has a correlation of 0.72—provided the trained observers perform as well as the calibrated laboratory equipment. On the other hand, however, results indicate fibre curvature not to be a reasonable indicator of mean fibre diameter differences across farms. Farm-effects on fibre curvature are large and may explain the difficulties cashmere growers experience when they visit other farms to visually evaluate cashmere goats prior to purchase. This work indicated that heavier goats are likely to produce cashmere with a lower fibre curvature. As this relationship did not differ between farms, it is reasonable to conclude that all goats exhibit this phenotypic response. Using cashmere fibre curvature (crimp frequency) as a tool for changing mean fibre diameter or selecting homogenous batches of fibre for sale will be reasonably effective within a farm, but is not a reasonable indicator and predictor of mean fibre diameter differences between farms.