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Developing the Finest Colored Huacaya Alpaca Herd in the World

Alpacas Are Just Fine -
Should They Be Finer?

by George H. Davis

Factors affecting fiber diameter in alpaca fleeces are presently the focus of considerable industry interest. In some cases, breeders have established fineness as a major selection criterion with the aim of producing consistently fine fleeces. The merit of this approach depends on whether clear market premiums for fineness exist because one attendant result may be a trade-off in fleece weight. In the September 1995 issue of Fine Wool Review, a market analysis of fine sheep wool carried out by Wools of New Zealand shows that as fiber diameter decreases below 22 microns, price per kilogram

Where llama crosses entering the alpaca gene pool are a concern, fiber diameter may be a key measure to determine if llama genes are present. Whether mean fiber diameter, variation of fiber diameter (measured as either standard deviation or coefficient of variation), or percentage of coarse fibers is the best indication of llama ancestry has been the subject of some debate. Mean fiber diameter is the least informative of these measures where the aim is to identify the presence of llama genes.

Nutrition can have a profound effect on alpaca fiber. In a comparison between alpacas grazed on native pastures and those grazed on alfalfa in Peru, Allan Marshall demonstrated that adult and young alpaca grazed on alfalfa had heavier liveweights and produced heavier fleeces. The adults on alfalfa were 16 percent heavier and produced an extra 34 percent of fiber, whereas the crias on alfalfa were 50 percent heavier that those on unimproved pasture (averaging 66 versus 44 kilograms at fifteen months of age) and produced 79 percent more fiber (averaging 1.88 versus 1.05 kilograms). Unfortunately, fiber diameter was not measured.

When alpaca research commenced at the Tara Hills High Country Research Station in the South Island of New Zealand in 1989, the expectation was that under better nutrition the liveweights would increase, fleece weight would increase, and, based on experience with sheep, some coarsening of fiber would result. The phenomenon of hunger-fineness is well known in Merino sheep. It turned out that the apparent effects of nutrition on fiber diameter in alpacas were much greater than anticipated. The one hundred two- to four-year-old research alpacas imported from Chile averaged 45 kilograms when they entered quarantine in Chile in May 1989. Within a month of completing quarantine in New Zealand, they averaged 64 kilograms and were shorn as a starting point for monitoring fiber production. Because the alpacas had been sourced from many flocks, their previous shearing dates were unknown. This precluded any meaningful measurement of fleece weight, but fiber diameters were measured by Dr Trumen Wuliji from midside samples collected at the first Tara Hills shearing. Further measurements were made annually at shearing each October At Tara Hills the alpacas grazed irrigated ryegrass and white clover pastures. Dr Wuliji's measurements showed that during the first two years at Tara Hills, the average liveweight increased to 68 kilograms, 51 percent heavier than the pre-quarantine weight in Chile, and the average fiber diameter increased by 6.8 microns, from 25.2 microns to 32.0 microns. In 10 percent of the flock, fiber diameter increased by more than 9 microns, 11.5 microns in the most extreme case.

Because the study did not include a control group fed unimproved pasture, the extent to which age affected fiber diameter and product cannot be separated from nutrition. Nevertheless, because most age effects on fiber production seem to occur in crias and tuis, the changes measured at Tara Hills were most likely a response to the better feeding of adult alpacas rather than to any age effects. Indeed, the study's most important implication for breeders and breed associations is that the increase in fiber diameter in the imported alpacas far exceeded that expected for sheep fed a higher plane of nutrition.

To determine the marked effect of nutrition on fiber diameter, breeders should therefore compare animals of the same age run together as one group. A valid comparison between flocks can be made through the technique of sire referencing, in which the same reference sires are used in two or more flocks and ranked within each flock. From this benchmark other sires within the participating flocks can be ranked. For example, a reference sire may leave offspring in one flock averaging 23 microns, but in another flock where the feeding is at a higher level, its offspring may average 28 microns. A second sire used in the first flock with progeny averaging 25 microns would be inferior to the reference sire (2 microns coarser), whereas an alternate sire used in the second flock, also with progeny averaging 25 microns, would be superior to the reference sire (3 microns finer). Selecting breeding animals on the sole basis of microns without comparative information obviously has pitfalls. Unfortunately, sire referencing is limited to larger flocks that can generate sufficient progeny of each male.

What this also means is that breed associations must carefully consider the effects of nutrition on fiber diameter before they impose rigid selection criteria. Overemphasis on fine fiber may mean that some alpacas are deliberately subjected to a starvation regime in order to meet a fixed micron threshold. If those who are guardians of the breed, who have the welfare of the animals at heart, instigated regulations that actually encouraged some breeders to mistreat their animals to meet impractical criteria, that would be most unfortunate indeed. Where the aim is to exclude llama genes, the concern should probably focus on the presence of coarse guard hairs. These are likely to be around 60 microns, so a standard that excluded animals with a specified percentage of these coarse fibers would better achieve the goal of excluding llama crosses. No amount of underfeeding will move guard hairs into the normal micron range for alpaca fiber.

Another important issue: Just because fiber diameter can be objectively measured is not necessarily a reason to use it as a measurement. Because alpaca fiber has a smooth profile, with almost invisible scales, it has a characteristically soft handle. Few people can subjectively distinguish between 22-micron and 30-micron alpaca fiber, and in many situations the end use will be the same. It is the coarse guard hairs that affect the appearance and feel of garments made from alpaca fiber, so selection pressure should be against those individuals producing this type of fiber in the main fleece. Visual inspection of an animal can usually detect the presence of guard hairs. Where a niche market requires fleeces of a specified fineness, however, measurement of diameter in individual fleeces is clearly needed to meet the processor's specifications and to aid in selecting replacement breeding stock. Objective measurement also can determine the percentage of guard hairs, which can then be used as a criterion in selecting replacement breeding stock. In other circumstances, interpreting fiber diameter measurements with caution may be the wisest approach.

1. One kilogram equals 2.2 pounds.

George Davis has published 130 papers on sheep, cattle, and alpaca breeding and production based on twenty-five years' experience in New Zealand and Korea. In 1994, he received the pestigious McMeekan Memorial Award from the New Zealand Society of Animal Production for outstanding service to agriculture. He has been a speaker, primarily on subjects related to fiber production in alpacas, at several Australian Alpaca Association national seminars and was a guest speaker at the 1995 AOBA conference.