Cuticle and cortical cell morphology and the ellipticity of cashmere are affected by nutrition of goats

Abstract

Cuticle scale edge height and frequency are used to identify animal fibres but exhibit a large range in dimensions, the reasons for which have not been elucidated. Cuticle and cortical cell dimensions along with the ellipticity of fibres were investigated in cashmere samples from a controlled nutrition experiment. Cuticle scale frequency, cuticle thickness, cortical cell dimensions and ellipticity were affected by nutritional treatment, with significant differences between cashmere from goats fed to grow and those which maintained live weight or lost weight. Cuticle scale frequency, cell thickness and ellipticity (contour) varied with fibre diameter, fibre growth rate and the size of the animals. Cuticle thickness and ellipticity were related. Cashmere grown by goats with higher levels of nutrition had longer cortical cells with greater diameter, volume and a higher length:diameter ratio compared with cashmere grown by goats in restricted nutrition treatments. The results show that the fundamental physical structures of cashmere do not have fixed dimensions. The consequences of the variations in cuticle morphology and ellipticity will be variation in surface friction, bending rigidity, softness, lustre, colour attributes, fibre cohesion during processing, felting and wear properties of textiles. There are also important consequences upon the determination of cashmere origin.