Implications to fleece evaluation derived from sources of variation contributing to cashmere fibre curvature
Introduction
For centuries cashmere has been regarded as the premier soft-handling animal fibre. One of the primary characteristics for the softness of cashmere is its low fibre curvature (McGregor, 2000, McGregor, 2001, McGregor, 2004). Until recently there was no objective information available on the fibre curvature (crimp) attributes of cashmere. Generally raw cashmere exhibits single fibre crimping, which can be reliably measured as fibre curvature (McGregor, 2001, McGregor, 2007). Furthermore, there are measurable differences between raw cashmere of different origins in: fibre crimp frequency; mean fibre curvature, mean fibre diameter relationships; and fibre crimp forms (McGregor, 2007). Eleven different forms of cashmere fibre crimp have been described and the occurrence of these crimp forms vary with the origin of the raw cashmere (McGregor, 2007). Commercially dehaired cashmere from more recent origins of production (Australia, New Zealand and USA) have significantly lower fibre curvature (fibre crimp) than cashmere obtained from the traditional sources such as Iran, Afghanistan, Mongolia and China. The predominant form of fibre crimping for cashmere derived from a particular origin together with the low rate of fibre crimping explains the low resistance to compression of cashmere and the differences in resistance to compression of cashmere between the different countries. The relationship between crimp frequency and fibre curvature of cashmere is quite strong, even though it covers a different range of values to those that have been observed in wool (McGregor, 2000, McGregor, 2001, McGregor, 2004).
Greater fibre curvature in raw cashmere has been associated with increased efficiency of cashmere dehairing and the production of longer dehaired cashmere (McGregor and Butler, 2008a). Furthermore the impact of fibre curvature on the processing, yarn and fabric mechanical properties of cashmere and superfine wool blend knitted fabrics have been evaluated (McGregor, 2001, McGregor and Postle, 2002, McGregor and Postle, 2004, McGregor and Postle, 2007, McGregor and Postle, 2008, Wang et al., 2006). By adding cashmere to wool, the knitted fabric softness, smoothness, flexibility and suppleness are increased, while pure cashmere fabrics have been found to be softer than pure wool fabrics. Generally, the blending of cashmere with low curvature (crimp) superfine wool has resulted in a change in the fabric mechanical properties or other physical attributes towards pure cashmere. These changes in the fabric mechanical properties are also translated as the fabric wear properties of cashmere and wool blend knitted fabrics (McGregor, 2001, McGregor and Postle, 2002).
While fibre curvature may be important in the processing and textile properties of cashmere, what are the implications for the cashmere producers? It has been established that for Australian cashmere, only a certain number of crimps are produced (McGregor, 2003). As such, crimp frequency in the Australian cashmere is time dependent, and not length dependent. Thus cashmere producers can manipulate the fibre curvature attributes of their cashmere by altering the cashmere production via nutrition management (McGregor, 2003). So, for example, well-fed goats, compared with under-fed goats, grew more cashmere which was longer and possessed a lower fibre curvature. Cashmere breeders can also manipulate the fibre crimp by genetic selection—as cashmere fibre crimp is moderately heritable (McGregor, 1997). Recently the impact of farm and age of the goat on cashmere fibre curvature was quantified, as these factors are commonly the only information available to breeders at animal sales or on farms (McGregor and Butler, 2008b). It has also been shown that cashmere fibre curvature along with cashmere staple length accounts for an additional 7–13% of the recorded variation in clean cashmere production after the farm identity and mean fibre diameter effects have been taken into account (McGregor and Butler, 2008c). The effect of reducing fibre curvature to below 70°/mm was to reduce the relative clean cashmere production.
As fibre curvature of cashmere has such an important impact on the cashmere softness, textiles, processing and production, this paper aimed to quantify the magnitude and direction of factors affecting cashmere fibre curvature (crimp), using laboratory measurements available to the cashmere producer.
Section snippets
General management
The data set and approach are the same as described earlier (McGregor and Butler, 2008c). Cashmere goats from 11 farms in 4 different states of Australia were monitored for live body weight (LW; kg) each month from December 2002 (Initial LW; kg) until June 2003 (Final LW; kg), just prior to shearing (Table 1). Some producers were unable to weigh each month (for example, during mating in autumn). Generally all goats in the flocks were monitored, but with some larger flocks 10 randomly selected
Results
The mean, standard deviation, and range in the number of sampled cashmere goats per farm were 398, 404, 70–1200, respectively. Considerable variability was recorded in the measured attributes, including fibre curvature (Table 2).
Discussion
The major share of the variation in fibre curvature of Australian cashmere is associated with mean fibre diameter and farm. Mean fibre diameter alone has accounted for 39% of the variation in fibre curvature and farm alone has accounted for 49% of the variation. Cumulatively the mean fibre diameter and farm accounted for 66.6% of the variation in fibre curvature, with age adding 2.2% and OFDA cashmere yield, initial live weight, fibre diameter standard deviation and clean washing yield combined
Conclusions
The major factors affecting cashmere fibre curvature were mean fibre diameter and farm. 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.
Acknowledgments
The cashmere producers who participated in this project, the Australian Cashmere Growers Association (ACGA), Riverina Fleece Testing Services, Albury, Mark Brims (BSC Electronics Perth) and the Rural Industries Research and Development Corporation, who partly funding this project, are thanked.
References (29)
- et al.
Determinants of cashmere production: the contribution of fleece measurements and animal growth on farms
Small Rumin. Res.
(2008) - et al.
The hairiness of worsted wool and cashmere yarns and the impact of fibre curvature on hairiness
Text. Res. J.
(2006) - Anon., 1997. Guide to Clip Preparation. Cashmere Aust. 19 (1),...
- Anon., 2001. In: A.J. Simmonds (Ed.), Australian Goat Notes. Australian Cashmere Growers Association,...
- Brims, M.A., 1993. New OFDA developments and the use of OFDA as a projection microscope. Report No. 22, International...
Measurement of fibre curvature: a review of work to date
Int. J. Sheep Wool Sci.
(1997)- IWTO-19-95, 1995. Determination of Wool Base and Vegetable Matter Base of Core Samples of Raw Wool. International Wool...
- IWTO-47-02, 2002. Measurement of the Mean and Distribution of Fibre Diameter of Wool using an Optical Fibre Diameter...
- et al.
Prediction of cashmere style using objective fiber measurements
Sheep Goat Res. J.
(1999) - et al.
Structural Studies of Sheep, Cattle and Goat Skin
(1988)
Cited by (14)
Sources of variation in fibre production and quality traits source of variation in down-bearing Patagonian goats and implications for developing a cashmere industry
2017, Small Ruminant ResearchCitation Excerpt :Producers can manipulate the fibre curvature attributes of their cashmere by altering cashmere production via nutritional management (McGregor, 2003). The effects of age, sex and farm of origin and fleece attributes and liveweight on the production and quality of Australian cashmere goats have been quantified (McGregor and Butler, 2009). In present work, both gender and liveweight were analysed, but only age was significant.
Characterization of mohair and cashmere in regions of Kazakhstan, Kyrgyzstan and Uzbekistan
2014, Small Ruminant ResearchCharacterization of camel fibers in regions of Kazakhstan and Uzbekistan
2014, Small Ruminant ResearchCitation Excerpt :This average was only surpassed in fineness by vicuña fibers (13.2 μm, Quispe et al., 2010). It was also surpassed in fineness by cashmere fibers from Australia (McGregor and Butler, 2009), Kyrgyzstan and the Pamir (15.8–16.7 μm, McGregor et al., 2009, 2011) and China (Bai et al., 2006; Wang et al., 2013). The overall arithmetic average MFD CV was 30.2 ± 0.2, which showed more within sample heterogeneity than that of South American camelids and cashmere, e.g. huacaya alpaca (20.2–24%, Lupton et al., 2006; McGregor, 2006; McGregor et al., 2012b), suri alpaca (25.9–26%, McGregor, 2006; Lupton and McColl, 2011), Australian cashmere (22.5%, McGregor and Butler, 2009) and Kyrgyz cashmere (20.2–18.8%, Kerven et al., 2009).
Estimates of genetic parameters and genetic changes for fleece traits in Inner Mongolia cashmere goats
2014, Small Ruminant ResearchCashmere quality of Raeini goats kept by nomads in Iran
2012, Small Ruminant Research