Fiber

An experiment was conducted to determine the effects of dietary protein intake after a period of weight loss on the wool components of staple strength for sheep with a history of low or high staple strength (18.0 vs 34 Nlktex). After being fed to lose 15% of their liveweight over 10 weeks, sheep within each staple strength group were assigned in equal numbers to either a low or high protein diet designed to re-gain initial liveweight in 8 weeks. Liveweight, feed intakes and the growth, fibre diameter and fibre length characteristics of wool were measured at regular intervals. After the weight loss and growth regimes were imposed there was no difference in staple strength between the low and high staple strength groups (14.4 and 14.9 Nt ktex, respectively). However, coefficient of variation (CV) of fibre diameter remained significantly different between staple strength groups. Wool growth rate at the time of diet change was the only significant component of wool growth and fibre measurements that was significantly correlated with staple strength. Supplying a high protein diet after a period of weight loss increased wool growth. This changed the position of break along the staple and increased the fibre diameter at the point of break from 13.0 to 13.9 J.1m without affecting staple strength. It also increased fibre diameter and mean fibre length growth rate. The low staple strength group had a significantly higher CV of fibre length than the high staple strength group. Fibre length growth rate to fibre diameter ratio was stable over time in the high staple strength phenotype but declined with time in the low staple strength line. The results suggest that large weight losses will reduce the difference in staple strength between animals with a history of large difference in staple strength. Rate of wool growth after the point of break did not influence this staple strength outcome. more »

The commercial value of unprocessed wool is determined by its intrinsic quality; an indication of capacity to meet both processor and consumer demands. Wool quality is evaluated through routine assessment of characteristics that include mean fibre diameter, coefficient of variation, staple characteristics, comfort factor, spinning fineness, fibre curvature and clean fleece yield. The association between these characteristics with wool quality stems from their correlation with raw wool processing performance in terms of speed, durability, ultimate use as apparel or carpet wool, and consumer satisfaction with the end-product. An evaluation of these characteristics allows wool quality to be objectively quantified prior to purchase and processing. The primary objective of this review was to define and explore these aforementioned key wool characteristics, focusing on their impact on quality, desirable parameters and methodology behind their quantification. An in-depth review of relevant published literature on these wool characteristics in sheep is presented. more »

In the article are introduced the fine structural characters of sheep hair, alpaca hair and mohair, and tested and compared their functions of strong stretch, crimp and friction. The result shows that the scale of alpaca hair and mohair is thin and dense. Alpaca hair has interrupted or widely-bodied pith cavity, whose scale is not as clear as the other two. Mohair and alpaca hair own a high initial mold and strength, little crimp and friction factor and worse fulling ability. Although they are hard for spinning, yet their product is of fine elasticity, crease resistance and size stability. more »

This study reports the latest research into alpaca and wool fibres. In particular, those properties that have received little attention in research literature have been examined. They include single fibre abrasion and bending fatigue, single fibre tensile properties, as well as resistance to compression behaviour. These properties are important because they affect the softness and pilling propensity of these fibres and the resultant fabrics. Clean wool and alpaca fibres were used in this study. Fibre abrasion/bending fatigue measurements were carried out using a Textechno FIBRESTRESS instrument. The resistance to compression (RtC) tests were carried out according to Australian Standard AS3535-1988. The results indicate that wool and alpaca fibres behave quite differently, even though both fibre types are of animal origin. Wool fibre resistance to compression decreases as fibre diameter increases while the opposite appears to occur for alpaca fibres. For both wool and alpaca the number of abrasion/bending cycles at fibre break increases with an increase in fibre diameter, it takes longer to break the alpaca fibres. Reasons for these differences have been postulated based on differences in fibre surface and structure between alpaca and wool. more »

This study compares the resistance to compression behavior of wool and alpaca fibers. It shows that alpaca fibers have a much lower resistance to compression than wool, and there is little correlation between the resistance to compression and the curvature for alpaca fibers. Yet for wool fibers, the correlation between resistance to compression and curvature is very strong and positive. The differences in fiber curvature and scale profiles of alpaca and wool, together with the test method for resistance to compression, may explain their different resistances to compression. more »