Fiber Study Report – by Chris Utterback
Your histogram
PBA Newsletter, May 2004
First a little history. Last summer the PBA board voted to spend $750 to fund a fiber study by Yocom-McColl laboratory. The goal of the study was to help Pygora® breeders understand their fiber and thus breed for better goats. It was also to help Pygoras compete in the very competitive international fiber market with factual information about Pygora fiber using the terms of the international fiber community. Lastly, but very importantly, it was hoped to establish objective criteria for grading Pygora fiber that could be used during the registration process.
What happened. Fiber was sent in from 14 different PBA member’s farms. It was collected from 57 different goats. Of those 57 goats, 13 did not fit the study because of age or because they were F1 animals. The samples were sent in June of 2003 and the reports sent out November of 2003. […]
The reports that came back had so much information that I asked for help evaluating them. I wanted to see what the reports said to the individual breeder as well as figure out what the reports meant for the Pygora breed as a whole. I asked Lisa Roskopf, a former PBA registrar, PBA sanctioned judge, and major Pygora breeder, and Lisa Zietz, a PBA sanctioned judge as well as a cashmere expert to act as a fiber committee. We have had two meetings so far and have one more that will happen in May.
So, that is where we are. This report will try and help everyone understand individual fiber reports from Yocom-McColl, so you can get the most out of them. The next report, coming in the next newsletter, will speak about what we found out about our breed as a whole.
Just for comparison: (terms will be explained below.)
Micron counts and fiber. Cashmere is below 19 microns, mohair is between 23 and 31. Above 31 microns is considered course for fine fiber markets.
A typical kid mohair report shows a mean fiber diameter of around 26 microns with a standard deviation of around 7. Fibers greater than 30 microns are around 25%.
A typical cashmere report shows a mean fiber diameter of around 16.5 microns with a standard deviation of about 3 microns and no fiber greater than 30 microns.
Individual reports: Each fiber tested was given a written report and 2 or 3 histograms, (white animals got the 3rd test for medulated fibers. This test could not be done on colored fiber.) The written report tells you in a nutshell what the lab thought of the sample. Having a single peak of fine fiber is the goal. If the report states there is a lot of guard hair it means there is a decreased yield. This is one of the things that breeders can work to improve by careful choice of breeding stock. (Note, It was found that all Pygoras have some guard hair, even those listed as type “A”.)
Now look at the report of fibers less than 30 microns. ( a sample report is provided at the bottom of this page for those who have not seen one.) The line on the bottom is fiber diameter, how fat the fiber is. The line on the side is what percent of fibers fit into that size.
Under the laboratory data section it lists:
Mean Fiber diameter. This is the average diameter of the sample, the smaller the number the better.
The Standard Deviation is how spread out the curve is, how consistent was the sample. The more different types of fiber the greater the standard deviation number, the less desirable the fiber.
Coefficient of Variation. This is a statistical measurement used to again point to consistency. The less consistent the fiber is the wider the bell curve will be and the greater the coefficient of variation.
Comfort Factor is a measurement used to show how soft the fiber is. It is calculated by subtracting the percentage of fibers over 30 microns, (the ones that are stiff and poke), from 100. The higher the comfort factor the softer the fiber.
“Prickle factor”, is not used in this report but is used by some experts. It gives you the same information as comfort factor but looks at it from the opposite direction. It measures the percentage of fibers greater than 30 microns. The higher the prickle factor the more pokey, or stiff fibers there are in the sample.
Curvature of the fiber is related to crimp. The more curvature, the more crimp. Usually the more crimp, the finer the fiber. So a high number is a good thing. It means more crimp. The standard deviation of curvature is again a measurement of consistence, the more consistent the lower the number.
Those who did the fiber study will have a report for fiber greater than 30 microns. It gives the same information as the report described above but for fiber over 30 microns. It is basically for fiber that will has a high “prickle factor” or low comfort factor. This fiber is mostly guard hair. This report is not as important as the one for fiber less than 30 micron report.
Those who sent in samples of fiber for the study that was white or very light will have a medulated fiber report. Medulated fibers are guard hairs or, if their center is greater than 60%, kemp fibers. (This report is a bit hard to read as it has the histogram of the fibers less than 30 microns, the lighter grey as well as the medulated fibers, the darker grey. ) What the report tells us is some of the same information.
Mean fiber diameter: you would expect the mean fiber diameter to be less for type “A” goats, their guard hair should be silky and have little separation. It should be very high for type “C” goats where fiber and guard hair should have a lot of separation.
Coefficient of variation should be high for a type “B” Pygora as this type of fiber should have two different types of guard hairs.
Objectionable fibers are the very course fibers that you can see with the naked eye. They look chalky and do not take dye.
Flat fibers are fibers with so large a center they collapse like a drinking straw. The more there are the more kempy is the coat.
Medium medulated fibers are those with less than 60% modulation.
Have I driven you crazy yet? Don’t worry, just take a minute and look over your report. The most important things is the mean fiber diameter and standard deviation and comfort factor.
[…]Next issue will be the second report on the fiber study. It will let you know what was discovered about Pygora fiber as a breed and may help us define which animals to breed and where the Pygora will go in the future. This is exciting stuff for anyone who is serious about producing a consistent supply of fiber for the fiber markets. In the mean time, keep sending in those fiber samples to Yocum-McColl. The more animals we have in a database the better our conclusions will be.
Crimp: How kinky the fiber is. Waves per lock.
F1: First generation cross between two recognized breeds. The progeny of that cross, if it breeds true (that is reproduce a copy of themselves), can be considered a new breed.
Kemp: This is a negative term used to describe super heavy guard hair with modulation greater than 60%. It may be straight, brittle, hairy and stiff, or kinky. Kempy fibers vary depending on the breed of animal. A fleece with more guard hair than fine fiber is also sometimes called kempy.
Histogram: A report that is displayed in a bar graph that depicts the frequency of specific traits in relation to the whole.
Medulated vs non-medulated fibers: Guard hair is medulated, it has a space in the middle similar to the marrow space in some bones. Medulated fibers are coarser than non-medulated ones and tend to be stiffer and resistant to absorbing water.
Separation: The difference between guard hairs and fiber.
Yield: The amount of usable fiber from a sample of fleece.
PBA Fiber Study – Part 2
Fiber Study Report – by Chris Utterback
The End. It’s just the beginning
PBA Newsletter, August 2004
When I first proposed the fiber study to the PBA Board I had three goals in mind. My first goal was to establish some objective findings that would help with classifying Pygora fiber types. My second goal was to establish some basic information about Pygora fiber that would help us compete in the exotic fiber market. I hoped the study would give us information to help buyers compare Pygora to the other exotic fibers. My third goal was to help any of PBA’s members that might be interested understand fiber reports. They could then use the reports as one more tool when choosing breeding stock.
PBA funded the study with $750. so we were able to use 57 goats in this first study. (41 senior animals, 16 juniors, (no animals under a year were used)/ 6 bucks, 42 does, and 9 wethers). The fleece was subjectively classified into fleece types before it was sent to Yocum McColl. There were 7 type “A”, 35 type “B”, and 15 type “C”. Granted, 57 samples is not a very big sample but it is a very important start.
There were two categories of reports from Yocum McColl. One was for fiber 5 to 300 microns, a second category was for fiber 30 microns and less. I have used the results from the 5 to 300 micron fibers for this report to you because I wanted to report on all fibers a Pygora goat can produce and not just the finest fiber. As with any research project, you never know where the information will take you when you start.
Goal 1, objective findings for fiber testing.
My hopes of coming up with a numerical “magic” number to help the registrar, objectively classify Pygora into “A”, “B”, or “C” was not as successful as I had hoped. As I said, the fiber samples had been subjectively fiber typed before they were sent in to Yocum McColl. All the fleece that was sent to me for the study went to Yocom McColl so there was no fiber to compare with the reports that were sent back. Luckily, there was a breeder who still had the rest of the fleece from their study goats. This was invaluable because it allowed us to compare the fiber with the numbers from the tests.
The category that came closest to providing a standard for classifying Pygora into types was average curvature. Average curvature is how “crimpy”, or wavy the fiber is. They actually take a 2-millimeter sample and look at the degree of curves in the fiber. The greater the degree of curve per millimeter, the finer the crimp. The results showed that the average curvature for type “A” was 17.76: type “B” was 25.81: and type “C” was 35.78, but the numbers are not consistent enough yet to make a definite statement that would let the registrar use set up a range of results for each fiber type.
Guard hair / medullated fibers.
One of the current ways to help identify Pygora fiber into fleece types is to look at the guard hairs. Our current breed standards state that type “A” should be single coated and have no guard hair, type “B” should have obvious guard hairs, and type “C” has one very coarse guard hair. The testing showed something different, there were two kinds of guard hair found, a very fine one and a coarse one. All the samples of Pygora in the study, regardless of fiber type, had one or both types of guard hair. Type “A” had the fine silky type of guard hair, type “B” had a fine silky one and a coarse one, and type “C” had a very coarse one. I am going to report on two of the reports regarding guard hair, the medullated fibers and objectionable fibers.
The medualted fiber report tells the number of all fibers in a sample that have a hollow core. This includes the silky and the coarse guard hair. To get the results for the medullated fiber report, 10,000 fibers of each sample are looked at and the number of medullated ones are counted. So the results are so many guard hairs per 10,000, the lower the number, the higher the yield of top grade product. This test can only be done on white or cream colored fleece because the test is done by shining a light through the fiber to find those that have the hollow core. The light will not shine through colored fiber. The average result for type “A” was 474 medullated fibers: type “B” 855: type “C” 190. As you can see, type “B” has by far the most guard hair. (There was only 1 type “C” that was tested because all the other type “C”s were colored. This animal may not be typical. It had a great yield with only a few guard hairs, but until we test more type “C” animals we can’t really use this information to describe type “C” fleece in general.)
A sub-report of the medullated fiber report was “objectionable fibers”, again measured per 10,000 fibers. Objectionable fibers are those medullated fibers that are visible to the naked eye and are chalky and don’t take dye. This test, like the medulated fiber report can only done on white or cream fleece. A small number shows that the fiber had a higher yield of fine fiber. There were less prickly fibers. This means the sample will be softer.
The mean number of objectionable fibers for all Pygora fiber types was 417 per 10,000. The individual results were: for type “A”, 170: for type “B”, 529. Remember, there was only 1 type “C” fleece that was tested for objectionable fibers and the result was 32. The type “A” goats were fairly consistent with results from 112 to 210 objectional fibers per 10,000. The type “B” goats were much less consistent with values from 17 to 1351. Most of them were between 100 to 700 but still, a very large variation. This makes it difficult to use this information as a test for classifying fiber types. Again, only 1 type “C” was tested. We need more information. It may turn out that this particular goat is the exception rather than the rule. We need to test more goats.
Goal 2, help PBA members compete in the exotic fiber market.
Micron count: how fine is the fiber. The smaller the number, the finer the fiber. Yocum McColl reported the micron count as “average fiber diameter”. The first thing asked by most exotic fiber buyers is micron count. We can now play the numbers game with real test results. Bottom line? In general, most adult Pygora, regardless of fiber type, runs within the kid mohair whose average is 26.7 with a standard deviation of 7.3. As a matter of fact, many of the samples had comments from the testers that said “typical kid mohair”.
We can also look at Pygora compared to cashmere. The average fiber diameter for cashmere is 16.5 microns with a standard deviation of 3 microns. (This means that the micron count could be as low as 13.5 or as high as 19.5). Only a few type”C” pygoras tested this fine. Average fiber diameter for the combined fiber types of Pygora was 27.02. Remember, the average age of the study Pygoras was 4.4 years. This is important to note because all fiber gets coarser an animal ages. Typical adult mohair is 34 microns. Only 3 goats in the study tested this high. Individual average counts for Type ”A” is, 29.35, SD of 3.93: Type “B” is, 27.58, SD of 3.76: Type “C” is, 24.87, SD 3.1. As you can see, in general, adult Pygora tests as fine, or finer than, kid mohair.
Comfort factor was also measured. Comfort factor is an objective number that reports how much of the fiber in the sample is soft, under 30 microns and how much is prickly, over 30 microns. (The number of fibers over 30 microns is subtracted from 100.) The higher the comfort factor the softer the fiber, 100 being perfect. There was no information on typical comfort factors for cashmere or mohair.
The average comfort factor for Pygora was 80.36 for all fiber types. Type “A” had the lowest at 68.37, type “B” was 79.4, and type “C” was 88.2. It may seem backwards to see a better comfort factor for type “C” rather than type “A”, since we all know, type “C” has very course guard hairs. I think the reason is that many type “A” Pygoras have an average micron count close to 30, so their whole fleece, for the sake of this calculation, is put in the prickle column. This shows why you can’t just judge a fleece by the numbers.
Now for the bad news, there is lot of variation among the samples of Pygora, even within the fiber types. Type ”A” average fiber diameter went from 24.54 to 35.13. The comfort factor went from a high of 87.65 to a very low 34.85. Average fiber diameter between type “B” fiber goes from a high of 34.87 to a low of 21.13. Comfort factor runs from a high of 92.89 to a low of 51.42. Type “C” micron counts go from 19.26 to 28.89. The comfort factor goes from 96.79 to a low of 80.48.
Goal 3, give breeders another tool when choosing breeding stock.
The results of the fiber testing tests can give breeders one more way to help them choose which genes to put together. The tests point out deficiencies and strengths in the fiber of each individual animal so the breeder can more easily choose an animal that will improve their herd.
That said, we can’t rely totally on fiber tests to give us the answers to choosing breeding stock. Besides conformation, there is still the very important and subjective “handle” or feel of the fiber that must be considered. What a fiber person feels when they touch a fleece is something gained after years of working with fleece. It is a feel that will tell them what to expect from a certain fleece, how it will work up, and how to use it. It is an important factor and must never be ignored. Of coarse, you can’t sell “feel” over the Internet, and this is what makes objective testing so important.
My opinion:
As I already explained, the results of Pygora fiber testing showed that Pygora fiber really is as wonderful as we thought. The problem is, the results are not very consistent yet. I believe if the Pygora is going to compete in the competitive exotic fiber market, we need to test our breeding stock, especially our bucks, and make them conform to standards and remove those that are out of line. Animals with high micron counts and-or low comfort factor for example. Breeders should more and more move to select breeding stock that has been tested. Even better, the parents test results should be looked at. By choosing only animals that can help you reach that magic number of not more than 26.7 microns and have high comfort factors, and low number of medullated fibers will quickly improve the Pygora breed. (Remember, comfort factor is simply the percentage of fibers over 30 microns subtracted from 100%. Fiber over 30 microns has a stiff feel and is usually not used next to the skin. Fiber over 30 microns is still useful for projects that require more strength but it usually sells for less money.) Also, remember, in general, as any animal ages the fiber gets more coarse and more guard hair gets produced which is why getting tests on the parents of kids before you buy is a good idea. If breeders will spend the small fee for the fiber tests, they and PBA will reap the rewards. Other breeds have improved quality through selective breeding and so can we.
You don’t have to be a breeder to get value out of fiber testing. I think that anyone who is selling fiber will help their sales by displaying fiber reports on their sale fiber.
Before I close, I want to really thank my two committee members, Lisa Roskopf and Lisa Zietz, for taking time out of their busy days to come to some long sessions with a lot of numbers and graphs. They graciously and unselfishly contributed their expertise in evaluating the reports. Thank you both !!
