Influence of nutrition, fibre diameter and fibre length on the fibre curvature of cashmere

Abstract

Raw and dehaired Australian and Chinese Liaoning cashmere were evaluated for cashmere fibre curvature, cashmere fibre length, resistance to compression, and mean fibre diameter. Tested cashmere originated from commercial lots, and previous experimental samples. In Australian goats, cashmere fibre curvature was dependent on nutrition. Goats fed to lose weight grew cashmere with significantly (P<0.05) increased fibre curvature compared with goats fed to gain weight (61 v. 47°/mm) but total fibre curvature (fibre curvature × fibre length) was not affected by nutrition treatment. In raw Liaoning cashmere, there was a significant (P<0.001) difference between each age and sex group in fibre curvature (bucks 52; does 65; kid bucks 78°/mm). Increasing Liaoning cashmere staple crimp frequency by 1/cm was correlated with an increase in fibre curvature of 6.5°/mm (r2 = 0.61). In raw and dehaired Australian and Liaoning cashmere, increasing mean fibre diameter and cashmere fibre length was associated with decreasing fibre curvature (for each 3 μm increase in mean fibre diameter fibre curvature declined 10–41°/mm; for each 10 mm increase in cashmere fibre length fibre curvature declined 3–13°/mm). Increasing cashmere mean fibre diameter was positively correlated with dehaired cashmere fibre length (for each 3 μm change in mean fibre diameter there was a change of 7–23 mm in length). In Australian and Liaoning cashmere, the direction of responses to changes in cashmere fibre attributes measured on the fibre curvature was similar. In raw Australian and Liaoning cashmere, increasing the ratio of cashmere fibre length:mean fibre diameter was associated with reduced fibre curvature. It was concluded that the high fibre curvature of Liaoning cashmere may be a consequence of low mean fibre diameter and short fibre length resulting from a production system where goats are relatively poorly fed. The results suggest that for Australian cashmere, only a certain number of crimps are produced. As such, crimp frequency in Australian cashmere is time dependent and not length dependent. Producers can manipulate the fibre curvature attributes of their cashmere by altering cashmere production via nutrition management. Preparation and testing procedures for the selling of raw cashmere and definitions of cashmere may need to be revised to include fibre curvature.