Fibre Notes


What is high yielding Australian Cashmere

What is high yielding Australian Cashmere? Explained through the use of photos.

© Trish Esson.

Alpaca Fleece Micron Measurement

Alpaca Fleece Measurement

Cashmere Connections has been purchasing Alpaca Fleece based on subjective measurement. Some growers have objected to the fibre assessments given because they have test results from mid side fleece samples which differ from Cashmere Connections' view. This paper attempts to answer two questions.

  1. How useful is a mid side sample test in ascertaining the value of a fleece?
  2. How good is Avtar at estimating the production value of a fleece?

The use of mid side samples to evaluate fleeces for breeding purposes is questionable (see papers below). When interloting fleeces for processing, mid side samples are definitely inappropriate.

© Charles Esson. No rights reserved.

Optimising sampling techniques and estimating sampling variance of fleece quality attributes in alpacas

Huacaya and Suri alpacas (n = 120) of varying age, live weight (LWT) and sex (female, male) were selected randomly from four farms in southern Australia. At shearing, fleeces were divided into four components: saddle (S), neck (N), pieces (P; front and back legs, belly, apron) and the midside sample (MS). Components were weighed, sampled using the grid sampling technique and fleece attributes measured: clean washing yield (CWY), mean fibre diameter (MFD), coefficient of variation of the MFD (CV(D)), incidence of medullated fibres (Med), mean medullated fibre diameter (MedMFD) and coefficient of variation of the MedMFD (MedCV(D)). The MS and saddle grid sample (SGS) were used to create models to predict the fleece attribute of the total fleece (TF), saddle and neck fibre. For each fleece attribute MS had lower values than SGS and TF (P < 0:005) and SGS, except for CWY, had lower values than the P and TF (P < 0:005). The means were: MFD MS 27.5 mm, S 28.8 mm, N 28.7 mm, P 37.6 mm, TF 31.2 mm; CV(D) MS 24.3%, S 27.0%, N 28.6%, P 30.6%, TF 28.1%; CWY MS 90.2%, S 91.4%, N 88.9%, P 92.8%; Med 24.4%, S 33.1%, P 44.5%, TF 35.2%; MedMFD MS 32.7 mm, S 34.4 mm, P 41.1 mm, TF 36.0 mm; MedCV(D) MS 19.4%, S 22.3%, P 25.9%, TF 23.4%. The MS was found to be an appropriate sample from which to predict the MFD and CWY. CV(D) was only satisfactorily predicted by the SGS (r = 0:88), with the exception of the neck fleece, for which neither the MS nor SGS could provide an accurate predictive model. The MS did not sufficiently account for the variation in Med (r = 0:73 - 0.79). The SGS gave accurate prediction of Med (r = 0:98). Sex effects were detected in models for TFMFD, NMFD and TFCV(D). LWT effects were detected in models for NMFD, NCV(D) and TFMedMFD. SGS often gave a more accurate prediction of a fleece attribute but it requires the removal of the entire fleece, whereas MS can be removed by shearing a small area or can be removed during shearing with a minimum of effort. Sampling variance for SGS was generally two to four times greater than the sampling variance for MS with the 95% confidence limits (CLs) for SGS being about double those of MS for most parameters except for clean washing yield (CWY) which were similar. Sampling variance for the incidence of medullated fibres in SGS was very high. The large 95% CL for all the tested fibre attributes indicate that alpaca breeders and advisors need to consider taking suitable duplicate measurements and other precautions during breeding and animal selling programs.

AylanParker McGregor Sampling of alpaca fleeces SRR 2002.pdf

© Crown Copywrite. For use for educational and research purpose only.

Variation in and sampling of Alpaca fleece

To help breeders evaluate alpaca fleece attributes the starting point is understanding the types of variation found in and between fleeces; the most appropriate method of sampling alpaca fleeces; and the application of this information for evaluating fibre test results. This article is based on research conducted in Australia.

Variation in and sampling of Alpaca fleece Jan07.pdf
© State of Victoria, Department of Primary Industries

Sources of variation in fibre diameter attributes of Australian alpacas and implications for fleece evaluation and animal selection

Sources of variation in fibre diameter attributes of Australian alpacas and implications for fleece evaluation and animal selection were investigated using data collected in the years 1994-97, from 6 properties in southern Australia. Data were analysed using REML (multiple regression analysis) to determine the effect on mean fibre diameter (MFD) and coefficient of variation of MFD (CV(FD)) of age, origin (property), sex (entire male, female), breed (Huacaya, Suri), liveweight, fibre colour, individual, and interactions of these effects. The mean (n = 100) age (range) was 4.2 years (0.1-11.9), liveweight 72.0 kg (12.0-134 kg), MFD 29.1 um (17.7-46.6 um), CV(FD) 24.33% (15.0-36.7%).

A number of variables affected MFD and CV(FD). MFD increased to 7.5 years of age, and correlations between MFD at 1.5 and 2 years of age with the MFD at older ages were much higher than correlations at younger ages. Fibre diameter "blowout" (increase with age) was positively correlated with the actual MFD at ages 2 years and older. There were important effects of farm, and these effects differed with year and shearing age. Suris were coarser than Huacayas with the effect reducing with increased liveweight; there was no effect of sex. Fleeces of light shade were 1 um finer than dark fleeces. CV(FD) declined rapidly between birth and 2 years of age, reaching a minimum at about 4 years of age and then increasing; however, CV(FD) measurements on young animals were very poor predictors of CV(FD) at older ages, and the response of CV(FD) to age differed with farm and year. Suris had a higher CV(FD) than Huacayas on most properties, and MFD, liveweight, and sex did not affect CV(FD). Fleeces of dark shade had higher CV(FD) than fleeces of light shade in 2 of the years. It is concluded that there are large opportunities to improve the MFD and CV(FD) of alpaca fibre through selection and breeding. The potential benefit is greatest from reducing the MFD and CV(FD) of fibre from older alpacas, through reducing the between-animal variation in MFD and CV(FD). Sampling alpacas at ages <2 years is likely to substantially decrease selection efficiency for lifetime fibre diameter attributes.

© CSIRO 2004