Our breeding goals prioritize three primary factors for improvement in animal phenotype and genotype: 1) fiber fineness, 2) consistency of fiber fineness, and 3) overall animal conformation to the breed standard. The first two goals are consistent with the most highly valued fiber qualities according to experts in the fiber and textiles industries. Fiber quality is measured and monitored via periodic (usually annual) standardized laboratory analysis of a fiber sample shorn from the main blanket area (middle side) of each animal. A fiber analysis report presents a graphical depiction of the measured fineness of each fiber in the sample in the form of a histogram (see figure below). The vertical axis depicts the percentage of fibers in the sample that fall within the thickness “bins” presented on the horizontal axis.
Fiber fineness is reported in terms of the Mean Fiber Diameter measured in micrometers (microns). As an alpaca ages, the thickness of its fiber tends to increase — on average 2-3 microns per year. As part of our breeding plan, we seek to breed animals whose fiber tends to retain fineness (thickens slower) with age. Specifically, our goal is to produce alpacas that yield fiber with a Mean Fiber Diameter of 18 microns or less at two years of age and retain a fineness of 23 microns or less at age five — and consistently pass on those same traits to their progeny.
Fiber consistency is reported in terms of Standard Deviation (specified in microns) of the entire fiber sample from the Mean Fiber Diameter and/or the Coefficient of Variation (reported as a percentage) — essentially the same information, just stated in different terms. In either case, a smaller number is better in terms of the consistency of the fleece. Our breeding goal for fiber consistency is less than 20 percent Coefficient of Variation.
Another factor reported in fiber analysis related to fiber consistency is the percentage of fibers in the sample with a diameter greater than 30 microns. This is important because fibers thicker than 30 microns contribute a detrimental “prickle factor” to the yarn and fabric produced from that fiber. So, again, the smaller the number the better in terms of overall fiber quality. Our goal is to consistently produce animals that maintain less than 5 percent Fibers Greater Than 30 microns.
The presence in an alpaca of the positive traits as listed in the Suri Breed Standard, and absence of negative traits, is important for two main reasons. First and foremost, solid conformation in a breeding animal is a good indicator of its overall physiological health and lack of genetic defects. Secondly, many of the breed standard traits are the same assessment factors used by judges in the show ring. Therefore, breeding for sound conformation leads to the production of healthy, prize-winning offspring.