has certain characteristics that we breeders try to achieve in our breeding programs. It's not realistic to achieve ALL characteristics from one single breeding. The idea is to breed a female up to a herdsire whose fleece has the one characteristic that you hope to achieve from that one particular breeding. Fiber characteristics that we seek include the following:
- Color--alpaca is classed by ARI into 22 color categories, though in reality the specific colors range infinitely through black, brown, fawn, beige, gray, and white. The 22 color classes make it possible to group fleece colors for processing.
- Staple length--the length of fiber an animal produces between shearings.
- Density--the number of hair follicles per square inch. The denser the fiber, the greater the yeild at shearing. Dense fiber also deters vegetable matter from invading into the fleece.
- Fineness--a measure of the diameter of each of the hair follicles, generally measured in microns.
- Uniformity--the even distribution of all the characteristics that are valued in a fleece.
- Crimp/crinkle--the waviness present in huacaya fiber. In sheep's wool, the more uniform the crimp, the finer the fleece was thought to be. In alpacas this isn't necessarily true (suris exhibit almost no crimp), but it continues to be valued by North American alpaca breeders and gives huacaya alpacas their characteristic "teddy bear" look.
- Fleece weight--the full weight of the blanket fleece and seconds neck and leg fiber).
- Luster in huacayas or sheen/shine in suris, uniformity of color, and handle.
Focusing on Fiber Characteristics
It is impractical to select for all of these traits in one breeding, and some of these traits counteract each other. For example, a fine fleece will weigh less than a courser fleece of equal density. Most breeders have selected one or two of these traits to focus on in their breeding programs. Different traits are more or less valuable depending on the intended end use--commercial processing, hand spinning, felting, quilting, for show, etc. So its important to know your market and goals.
When evaluating fleece on an animal, know which factors you're looking for and judge the animal with your criteria in mind. It's typical to split the fleece in at least 3 areas (the center side, the front shoulder and the back rump) to judge the uniformity of the animal's fleece characteristics across the entire blanket.
Reading a histogram
Before selecting a herdsire, it's important that you get a recent fiber histogram from the owner. Most juvenile and yearling males have very fine fiber that will grow coarser with age. A histogram that is 3 or 4 years old is not helpful, as it doesn't tell you if the herdsire is one of those special boys whose fiber fineness holds past age three. A histogram reports on four important fiber characteristics:
- Average Fiber Diameter (AFD) indicates the fiber diameter in microns.
- Standard Deviation (SD) is a term representing an average of individual deviations (plus or minus micron values) from the mean or AFD. The smaller the Standard Deviation, the more uniform the population of fibers measured.
- Coefficient of Variation (CV) is the Standard Deviation divided by the Average Fiber Diameter multipled by 100 and reported as a percentage. The CV is used in the statistical analysis of different populations of fiber (different animals).
- %>30µn; (percentage of fiber greater than 30 microns)shows the coarse edge that determines the final use of the fiber. It has a relationship to the strength of the yarn processed from the raw fiber and influences "prickle" factor, the scratchy quality associated with coarser fibers. The lower this number, the softer and less scratchy the fiber.
This page was last updated on June 10, 2009.