Factors that Affect Fleece Histograms

Age, diet, hormones, stress and environment can all change a histogram.

An animal that was raised in Alaska on dry lot feed can expect a change in histogram when they are moved to Texas to pasture graze. 

Example

According to a study done at Tara Hills Stud in New Zealand, animals imported from Chile, where they were pasture grazed on rough forage, weighted 100 pounds upon arrival into quarantine.  Within one month their weight increased to an average of 141 pounds.  They were shorn at this point and tested for fleece diameters.  For two successive years the animal’s fleeces were tested at shearing time and at the end of two years the average weight of the animals increased to 150 pounds (51 percent heavier than pre-quarantine weight) and fiber diameter increased by almost 7 microns, from 25.2 to 32 microns.  In some animals the increase was 9 microns and the most extreme increase was 11.5 microns. This shows a direct correlation between fiber micron and diet.

Laserscan tchnology tests the cut end only, this histogram is a measurement of a moment in time in the life of alpaca fiber.

OFDA testing and the historical evaluation chart that it presents shows breeders the evidence of change due to factors in an individual animals life. (reference Whittick Fiber Mills Ltd worksheet on reading the OFDA chart.)

What is the importance of a histogram in relation to purchasing and breeding Alpacas?

A histogram is one factor in evaluating the quality and quantity of fiber on an individual alpaca.  When someone says to you that this particular alpaca is “great” based solely on a low micron count, you need to remember that  histograms can indicate

  1. Fineness at a given point in time
  2. Variation in fiber diameter at a given point in time
  3. Changes in fineness and variation over time (when multiple histograms or OFDA charts are present)
  4. A single factor, like a low micron is not sufficient information to evaluate fiber.

Interestingly, when micron measurements change due to any of the environmental factors that we have discussed the Standard Deviation and Coefficient of Variation will remain relatively stable.

Remember to engage your senses to evaluate all the other qualities of fleece rather than relying solely on a histogram.

Because there are so many factors involved in assessing fiber quality, what are the questions we should ask when evaluating histograms?

What was the age of the alpaca when the sample was taken? 

(Tui (first year) fleeces are not good representatives of fleece quality because they are always the finest and the animal has not finished growing).  However, the OFDA chart of a Tui fiber gives you a reading from the tip of the fiber or a Genetic marker of Micron since this measurement would literally be an in-utero measurement before being affected by outside environmental influences.

If you want to look at the histogram that gives you the best averages for the animals life you would want to look at age 2.

Can you provide histograms for the past 3-5 years?

(Change happens.  If great statistics can be verified over 3-5 years with very little change then you could have genes that predispose offspring to great fleece characteristics and you would like to include them in your breeding program.  Be aware that herdsire fleeces change with extensive breeding while the genetics for great fiber continue to be passed to the offspring.)

What was the weight of the clip corresponding to each histogram?

(Great fleece will not do a processor any good if there is no quantity to process)

Is the animal pregnant? Is she nursing? Is this a breeding male? Were there any changes in diet or feeding levels between the histograms?

(Remember all those environmental factors that can cause change, some of which can be improved, some of which cannot.)

Did the animal have any illness or extensive travel (Stress) in the past year

Ask yourself to what use you wish to put the animal?

  • Breeding for show — When you breed for the showring you are looking for the individual outstanding animal.  This is where we get a great deal of our genetic improvement for the next generations.
  • Breeding for a fiber production herd —We are still in the process of breeding enough animals in this country to have a commercial fiber industry.  However, when we do arrive at that point the processors are going to want maximum uniformity to reduce waste and make processing more efficient.  A breeder working toward that end might focus on producing a herd that has uniformity of fleece characteristics, not only on one animal, but on all animals in the herd.  They might look for the best average they can get in fleece weight, staple length, tensile strength, color and fineness so that all the fiber can be sold in larger batches.  A breeder working toward that type of herd would want to know the fiber classifications currently used in fiber processing.

Fiber Classifications as recognized by Inca Group, Peru

Classification Micron Range

Royal Baby Under 20 micron

Baby 20-22 Microns

Superfine 23-26.9 Micron

Suri 27 – 31.9 Micron

Adult 27.5 –31.9 Micron

Coarse 32 Micron and above

Fiber Classifications as recognized in Canada

Classification Micron Range

#1 Under 20 Micron

#2 20-22 Microns

#3 23-25.9 Micron

#4 26 – 28.9 Micron

#5 29 –31.9 Micron

#6 32.1 - 35 Micron

Fiber Classifications as recognized in Australia

Classification Micron Range

Superfine Under 20 Micron

Fine 20-23 Microns

Medium 23-26 Micron

Strong 26.1 – 30 Micron

Extra Strong 30 Micron and above 

Note that each country has its own ideas about how to classify fleece.

Something that should be mentioned, even though we do not like to believe that it happens is fraudulent histograms.  There is currently no procedure in place for verifying that the sample being tested actually came from the animal that an individual says it came from.  No DNA testing is run on fiber samples, probably due to cost and time factors.  So if an unscrupulous person wanted to, he could send in a sample from a yearling female and state that it was from a registered 2 year old male and get a histogram back that listed that male’s information on the data for another animal. Not a very pleasant thought but one that falls under the old adage, “if it looks too good to be true, it probably is.”  It is just one more reason to make sure that you evaluate the animal fully.  Touch it, Feel fiber  samples, Ask questions about its history, then make your decisions.

Remember, a histogram is just one tool for evaluating fiber.  It provides valuable scientific information about fiber but it has to be incorporated with all the other factors that affect fleece to help the breeder determine a fantastic fleece.