To assess and grade an alpacas fleece you need to look at the following qualities:
• LUSTER: Sheen, gloss or shine
• HANDLE: Feel of the fleece in your hand
• DENSITY: The measurement of fibers in a square unit area
• ARCHITECTURE: Structure or lay of the fibers that make of the fleece
• CHARACTER: The quality of the crimp, staple length and formation of the lock
• FINENESS: Diameters of the fiber within the fleece
• CRIMP: Waviness of the individual fibers which distinguishes them from being straight
• CONSISTENCY: Uniformity of the crimp, staple length, character and density with the locks and throughout the fleece
• COVERAGE: What portion of the body supports continuously growing fibers.
Alpacas come in two fiber types - huacaya and suri. The huacaya (pronounced wa-ki-a) alpaca is characterized by a fiber that is dense, crimped, and wooly in appearance. This abundant coverage gives the huacaya a soft and huggable look and explains the overwhelming popularity the huacaya enjoys worldwide. Ninety percent of the North American alpaca herd consists of huacayas, and this plurality will remain virtually unchanged in the decades that lie ahead.
Huacaya
The suri (sir-e) is distinguished from the huacaya alpaca by its unique fiber characteristics. Suri alpacas are extremely rare. They represent only a very small percentage of the world’s alpaca population. The fiber grows parallel to the body while hanging in long, separate, non-crimped locks. Suri fiber locks are made up of high-luster fibers and drapes down the sides of the body in a twisted or flat form of various size. Suri fiber has excellent luster, a slick hand, and extreme softness. The suri alpaca is an excellent investment because of its rarity and inherent beauty.
Suri
Fiber and skin biopsy testing can be done through Ian Watt of Alpaca Consulting. Website information: http://www.elitealpacabreedingsystems.com/data.html
SRS® Skin Biopsy Testing
Follicle, Density and in-Skin Micron Count Data
by J.E. Watts
Introduction
The SRS breeding objective of increasing the density and length of fibres grown by fleece-coated animals is based on the pre-papilla cell research of Moore et al (1998), Pattern and morphogenesis in skin, Journal of Theoretical Biology, 191:87-94, and later unpublished data.
This work has demonstrated that the density and fineness of fibres is controlled by the size of the pre-papilla cell clusters formed in the foetal skin whilst fibre length is thought to be regulated by the signal strength of mitogen(s) produced by these cells (see www.srswool.com for details).
Pre-papilla cells
High fibre density requires a large starting population of pre-papilla cells in the foetal skin and for these cells to be distributed as small clusters to both the primary wool follicles and secondary wool follicles. Follicle formation is completed before the animal is born. Fibre length is also a measurable response of pre-papilla activity. So the package of desirable follicle and fibre characteristics we are seeking to breed in alpacas are:
1. very fine primary fibres of uniform diameters (eventually finer than the secondary fibres) this allows a greater proportion of the pre-papilla cells to be available to form secondary wool follicles.
2. high follicle density associated with high levels of secondary follicle branching (the latter equates to high secondary follicle to primary follicle [S/P] ratio this is an expression of many pre-papilla cells being available to form secondary follicles which, in turn, are formed by small clusters. Hence the secondary fibres are also fine, uniform in diameter and highly aligned.
If 1. and 2. are in place, the profiles will show two steep and narrow fibre diameter distribution curves with the red one (primary fibres) to the left of the blue one (secondary fibres)
3. very long fibres of uniform length.
These features are associated with skins that are thin and loose (Watts, unpublished data).
Medullated fibres
Medullated fibres are unwanted fibres which spoil the appearance of fabrics.
In horizontal skin sections, medullated fibres can be identified and counted within each follicle type.
This is an important capability. Whilst medullation tends to reside mainly in the primary fibres and disappears as fibres become finer, this is not always the case. In some animals, medullated fibres can still be present in fine diameter fibres and numerous.among the secondary fibres. Skin testing allows us to identify, and remove from the breeding pool, animals with these hidden problems.
Pigmented fibres
Skin testing also allows us to identify pigmented fibres in each follicle type. This also is an important diagnostic function.
For example, in a white alpaca we can determine if any pigmented fibres are still to be found and which follicle type(s) are affected. We can also determine whether pigmentation is a problem of coarse diameter fibres, and likely to disappear as fineness and uniformity of fibres improve, or is generally distributed throughout fibres.
Industry Standards
Alpacas considered of good fleece quality by current industry standards have, on average, a follicle density of about 40 follicles per square millimetre and an S/P ratio of 10 to 1.
Primary fibres are mostly medullated and about 10 microns coarser than the secondary fibres. The average fibre diameter in adult animals generally varies from about 20 to 30 microns.
The fibre length of young adult animals averages about 0.40 millimetres per day, and in old animals, about 0.25 millimetres per day. The higher the fibre length to staple length ratio, the higher crimp amplitude (that is, the deeper the crimp) is likely to be.
It is certainly possible to breed animals that are a lot denser, finer and longer than current industry standards.
The SRS breeding goals (as stated above) is to breed alpacas that have primary fibres finer than the secondary fibres, secondary fibres that are up to 10 microns finer than currently seen in adult animals, follicle densities above 85 follicles per square millimetre and S/P ratios above 20 to 1. Ultimately, no fibres should be medullated, irrespective of the age of the animal or the follicle type. The objective is also to improve fibre length to 0.70 millimetres per day or more and maintain this length throughout much of the animals life.
Fiber Testing:
OFDA 2000
http://alpacaconsultingusa.com/ofda/index.html
Yocom McColl Testing Laboratories Inc.
www.ymccoll.com
