- The measurements made on wool and the reasons for those measurements are examined. It is suggested that, if the alpaca fibre-processing industry is to move beyond being a cottage industry, it will have to adopt modern total quality management. It will also have to respond to customer demands for end-products at competitive prices and processor demands for repeatable quality. This will mean price will be determined by measured fibre properties and the key properties will almost certainly be diameter and whiteness (freedom from coloured fibre).
- Alpaca and llama fleece are classified as specialty or luxury fibers, but sheep fleece or wool tops the list of animal fibers used today. The camelids (alpaca and llama) are quite similar to each other in fiber and background, and though they bear some similarity to sheep, the differences between the fibers of these herding animals are outstanding.
- Processors and wearers still often judge the comfort of lightweight wool knitwear by squeezing the fabric to gauge how ‘soft’ it is, believing a softer feel or ‘handle’ will provide an excellent wearing experience and not prickle or irritate the skin. However, Sheep CRC research has shown this relationship to be unreliable. Reliance on this relationship means that uncomfortable wool knitwear is being produced and sold, which continues to reinforce the notion that wool is a prickly fibre. New objective testing devices for comfort and handle provide the opportunity to ensure all wool garments are fit for purpose and positively reinforce the exceptional comfort properties of wool.
Consequences of Differing Wool Growth Rates on Staple Strength of Merino Wethers with Divergent Staple StrengthsAn 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.
- 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.