The Good, The Bad and the Ugly
Home Page | The Good, The Bad and the Ugly
|The Good, The Bad and The Ugly
Here we will look at 3 different histograms from animals purchased by our farm as breeding animals from different breeders sources. We will compare them to the standard for cashmere as well as against each other.
The biggest things to look for on a histogram are the shape of the graph, the sample size, the Standard Deviation (SD), The Coefficient of Variation (CV) and of course the Mean FIbre Diamater (MFD). You might wonder why we rated MFD last in how we go about looking at a histogram. Well simply because, assuming the number falls within the cashmere range, it is not as important to us as knowing how consistent that fleece is and what is hidden in the fleece that we might not have been able to see when we visually assessed the fibre on the farm.
Now of course we don't want to see a high MFD on a kid fleece, but if you know your herd and their genetics as you will learn over time from having histograms done every year on your breeding stock, there are cases where animals may start out in the medium range for micron and never change more than a micron over their lifetime. They are, in short consistent over time so for me the micron is not the end all and be all since it is falling within the cashmere range. We have even had a doe test very close to being out of the cashmere range on a second fleece, but each year after that, she has gotten finer. This is not the norm, but I am glad I didn't cull her based on one fibre sample and no history on her families long term genetics. Sometimes a good doe is worth the gamble.
The other thing you will learn by testing your animals fibre yearly is when something may be very off in your herd or with a specific animal. It is normal to see a small change in the fleece results from one year to the next, but if you see a large change in a number of animals or even in one animal who is always very consistent, it can be an indicator that the animal is ill, or there was a dramtic change in their feed in the last year and may warrant your looking further into the reason behind the change.
A Good Cashmere Histogram
The above histogram is that of a doe and this is her 4th fleece. You can see that the graph itself is very thin vertically and very long horizontally. This indicates that there is uniformity in the fleece as most of the fleeces fibre falls between 8 and 22 microns as seen in the second colum from the left side of the page in front of the bars. Mic means micron. The count represents the actual number of fibres counted at each micron. Along the top of the graph is the scale to which the counted fibres are recorded to create the bars of the graph.
If we look at the longest bar, and trace it back to the numbers on the left, we see that 1218 fibres were counted at 14 microns. If we look to the top of the histogram on the right hand side, we see the Mean is 14.45. This is the average of the micron range in this fleece. It is slightly over 14 microns and you might wonder why, but if you look at the number of micron bars above and below the 14 micron bar you will see there are more bars below 14 microns than above, so when averaged this takes the number up a little and we arrive at this goats Mean Fibre Diameter or MFD of 14.45.
The standard deviation (SD) in this fleece 2.53. As indicated earlier the number we aim for in adults is a SD of 3.5 or less. The lower the number the more consistency in the sample. This is a very nice consistent doe. You will see below the SD that the Coefficient of Variation (CV) is 17.5%. As mentioned previously, this number needs to be less that 24% to meet the definition for cashmere fibre. Generally the lower the number the better as far as breeding stock go.
The sample size number can be seen on the right hand side at the top and here it reads 7696. This is a decent sample size so we can be assured that the histogram is a pretty good representation of this animals fleece. This is a fleece that was sampled using a 3 site sampling method, so she appears to produce nice consistent fleece right across her body and I can vouch for the fact that she does.
If you look above the left hand side of the graph you will see the curve. This number reflects the degree of curve per millimetre of fibre length and is the measure for the fibre crimp or style. As you can see this doe has a curvature of 83.1 which is a very nice stylish fleece.
A Bad Cashmere Fleece
This histogram is also that of a doe. I believe it was a second fleece, although this histogram does not tell us on the top. A histogram will only reflect the information at the top that you provide to the lab when sending your fleeces, so for quick comparison or evaluation it is best to include on your samples, at least the goats name, age, fleece number, your name and the goats sex.
Right off the bat with this histogram you see that the main part of the graph is half the width. On the histogram above, the depth was less than 1/3 of the width. Even if you call the graph ended at 27 microns, you can see the bulk of the fibres fall between 2 and 27 microns and this is a far wider range than the fleece at the top. So this fleece has a lot more variation in the fibre quality. This might be accounted for by variation within the individual samples or between the different sample sites or both.
You can see that the graph peaks at 16 microns but you can also see that ther are quite a few more bars below that line than above in this histogram, especially if you look at the shorter bars below the 27 micron line. You will notice these bars did not really show up in the good cashmere fleece. These bars, although not that many fibres at each one, may indicate finer guard hair or something worse in the fleece. At the very least they reinforce the lack of consistency in the microns in this fleece.The other thing to be leary of in a histogram that is shifted so far below the average is that the graph can actually be disguising a second peak which would indicate a third fibre type which is neither cashmere nor guard hair. This is not a fibre type you want to see in a goat you are calling a cashmere goat. If you look at the graph, you can almost see where the 19 and 20 micron bars might be the peak of a second fibre type with the top half of the bars hidden in the cashmere fibre counts.
If we look at the count next to the 16 micron line, you see it is only 345. This is a product not only of the wider ditribution of microns, but also of the sample size. If you look at that number you will see that only 3000 fibre's were sampled. Generally a larger sample size is better as this way we can be as sure as possible that the histogram truly reflects the fleece. This is where knowing your fleeces and having evaluated them subjectively comes into play. If you know that the animals neck is weaker than her midside and the samples were of the same size, then it is possible that more of the neck was sampled than the primary combing area and is unfairly represented in this histogram. Some people wanting to sample more than one site will send in 3 separate samples for one animal. It really depends what you are looking to use the information for in your own herd that determines how you sample.
The SD on this fleece is above 3.5 North American Standard, coming in at 3.96 microns, although her CV is 22.3 which is below the world wide standard.
Her curvature is poor at 48 degrees per millimetre, but still above the minimum of 45 set out in North America.
Overall this fleece could still pass for cashmere, but given her age and inconsistency, she is not a good cashmere goat and we would not use her in our herd for breeding.
This histogram is a second fleece on a buck.
We first see that the depth of the graph is almost equal to the width and this is with cutting the depth off at 30 microns. You will see that there is a definate second peak at 19 microns indicating third degree fibre's in the fleece. There are some smaller peaks at 30, and 36 microns, although here we are hopefully into the guard hair at that point, but that there is no distinction between cashmere and guard hair is very concerning and would make this fleece impossible to dehair.
The MFD is 18.55, barely hanging in to be cashmere, but it is obtained through averaging all the fibres counted between 2 and 40 microns. If we look at the first peak, it is at 16 microns, so if the bottom part of the graph looked like the first one in shape, this would not be too bad a histogram and this buck would likely have an MFD on his cashmere fibre of 17 microns (assuming a slight shift to the bottom as with the first fleece).
The SD is 4.98, well above the 3.5 standard. The CV is 26.9%, also well above the maximum of 24% for the world standard. This fleece is extremely variable and inconsistent. Certainly, not what we want to see in a cashmere fleece and especially a breeding buck. Remember you breeding buck contributes half his genetics to each doe's opffpsring you sevice with him. A bad doe can only make a couple bad kids a year, but a bad buck can make many bad offspring and this can ruin a herd in no time, especially if you are not actively evaluating and culling.
The curvature is 62.5 deg/mm which is still in the ball park, but not great for a breeding buck and not great for only his second fleece.
The sample size is only 3000, but when there is this much variation, especially in a young buck, a larger sample size would not make a difference in his fate. In an older buck very macho buck, this may be seen by hvaing sampled the coarser neck hairs. Still not ideal over the long haul for cashmere, but at least the coarseness has been "earned" in a mature buck.
This fibre is NOT cashmere, but if this was the only type of fleece I had seen and we bought a "cashmere" goat, how would we know any different? We could not necessarily "see" all of this variation in the fleece on our visual assessment, we just knew we didn't like it very much compared to some of our other fleeces and could feel it was lacking that cashmere magic. A simple, inexpensive test allowed us to "see" the extent of what was going on in the fleece and make the best choice for our herd in culling this buck. After all, breeding this buck to the doe on the top of the page would be a disservice to her and a waste of a year of her productive life.
Remember, it is up to each breeder to decide if an animal is good enough to be used in their herd for breeding. You have some easy and inexpensive tools to help you make the best choice for your herd and to help train your own eye and hone your subjective evaluations, so please use them. We have purchsed exceptional animals from breeders who cared very little about educating themselves as to what was and was not cashmere and we have purchased horrible animals from exceptional breeders. There are no quarantees in cashmere, but if you know your herd, know where you want to take your herd and have armed yourself with the skills to know what you are looking at and looking for, you can do great things with your herd and see the results you are looking for and that is a great feeling!
Other things to ponder ....
Just as an aside and to reinforce the point I made above. We would not necessarily remove an animal from our farm based on one histogram without having other concerns as so many things can make for one off year. Having imported several bucks from the US and having brought animals across the country, we have noticed that especially in the bucks, the year following the change, their fleeces will be off. It is not as noticeable in the does as they tend to get more attention and don't destroy all their mineral feeders so keeping them in optimum condition is easier. The older the animals are when the move occurs the longer a period of adjustment they require and the longer the fleece may be off. This is where knowing the animals production traits and genetic history, comes into play and allows you to give a good animal the benefit of the doubt. Usually by the next season the animal has adjusted and their fleece and fibre data return to normal.
We have noticed a similar instance with some of our aging does whose teeth are letting them down, where supplimentation with legume pellets has taken their fibre from medium to coarse in one season, but not beyond that. This does not mean these animals are not worth breeding for as long as long as they can be used safely -assuming she is in good health and her poor teeth are from age and previous management (long term feeding of high molassas containing feeds will cause tooth decay and injury can result in the loss of teeth which then erodes the stability of the remaining teeth), not from a genetic weakness. This is again where it is important to know the animals feed history before you bought them and that what and how you are feeding can impact your animals, to allow you to make good choices for their long term health and your breeding program.
In the case of the bad fleeced buck above, we retained him for a period of time, although we did not use him for breeding. We tested his fleece multiple times to ensure the histogram was not the result of something else since he did represent a very popular breeding line in Canada whose decendants have experienced much success. In this case, the resulting histograms was the same shape with poorer numbers each year. Of note though, was this buck had always passed our annual disease screening, but at age 4 he was failing to maintain weight despite his teeth still being good and appropriate parasite prevention etc. We went the extra step of having this buck euthanized and autopsied including histology on samples from all vital and minor organs, to be sure he had not been harbouring something we failed to pick up on in our screens. Thankfully, the results came back negative for everything possible, so this was a releif, but his fleece data could have been the first indicator of some larger issue. In this case, we suspect this buck simply had a poor constitution for lack of a better term and his genetics were not only reflecting this in his fleece data, but in his body condition as he aged. His fibre genetics may have in fact been stellar, we will never truly know, but his health genetics are not something we would have wanted to pass on in his offspring. Especially since research in sheep has shown that resistenaces to parasites, hoof rot and so on are highly heritable traits. In our experience a poor doing animal or one with a bad temperment are animals that should be culled, even if they have a stunning fleece or are from a long line of stellar animals. Really if you can not be safe around your animals, even during breeding season -and this goes for all livestock breeds, or they are so unthrify they need continuing extra care, you are moving your herd and your farms future in the wrong direction if you use them as breeding animals.