Calculating Coefficient of Inbreeding

A method of determining how related your sheep are to each other
or how related your sheep are to mine.

"Matchmaker, matchmaker..."

We often have prospective buyers email or call and ask if our sheep are "unrelated enough" to purchase a ram from us to breed to their flock. We are uncomfortable answering these questions for a variety of reasons.

Coefficient of Inbreeding

A better way to figure out whether or not a ram from our flock is right for you, is to calculate the Coefficient of Inbreeding. This is a number which tells you how wide or narrow the genetics are in a particular sheep. Then, if you have questions about whether a ram and ewe are "too related" or not, you can figure how wide or narrow the genetics would be in their theoretical lambs.

Here are a couple of very informative and useful articles that explain coefficient of inbreeding:

Handy Software Free for the Taking

Many flock management programs (that you can purchase) do this for you. You can also download a free program called FSpeed to calculate COI. This program will only work on a PC (not a Mac).

By going to this website you can download FSpeed. It is a very fast and easy program to calculate COI. I did my small flock, including a bunch of theoretical breedings that I was considering, in less than 2 hours. Of course if you have 300 sheep, it is going to take a lot longer, but chances are that some of them have common ancestors and that will speed up your data input. (More on that later.)

There's No Need to Fear...

Here are step-by-step instructions on how to use this program. All of this (and more) is listed in the Help file of FSpeed. I am just trying to simplify things a bit for those who might get a "technology headache" from the whole idea.

1. Download and install the FSpeed software from the website.
It will give you instructions on the screen and will also ask you if you want to create a shortcut on your desktop. (That is what I did; so I don't have to search for it.)

2. Make a file listing your sheep using Excel or Notepad:
You will need to make a file to list your sheep and their ancestors using either Microsoft Excel or Notepad. If you have the Microsoft Office package on your computer, then you have Excel. (Its icon has a big X on it.) Use Excel if you have it because I think it is easier and tidier. Excel already gives you columns (so you don't have to divide up your data with tabs). If you don't have Excel, then use notepad. Notepad comes free with every PC. Click on your START menu down at the bottom left of your computer screen, go to ALL PROGRAMS and then to ACCESSORIES. You will see one called NOTEPAD with a little blue picture of a pad of paper.

Instructions using Excel:

Read this even if you are going to use Notepad since the basic idea is the same.

Open Excel and get out the pedigrees for your sheep. You can use sheep names, ear tag numbers, registration number or a combination. Just make sure you assign one label to each sheep. For example, if "Fluffy" is also eartag number #130 and FBA registration number #12345, don't call her "Fluffy" in one place and #130 in another. The program will think she is two different sheep. I decided to use sheep names where they were available and FBA registration numbers where they were not. If you use names, my suggestion type them in all small letters, it will be faster and you have enough typing to do as it is!

I used only 3 columns (A, B, and C). The program gives the option of using 5 columns to do some fancier stuff, but these are supposed to be the easy instructions! Let's start with the first sheep in row 1. (It doesn't matter who you start with, they're all going to get done eventually.) In column A, we are going to write the name of a sheep. For my example, I will use my ewe Annika and type her name in row one, column A. In the second column (row 1; column B), I will type the name of her sire (father) - which is Usko. In the third column column (row 1; column C), I will type the name of her dam (mother) - which is Lumi. So my first row of the Excel file goes Annika - Usko - Lumi (sheep - sire - dam).

Now we will move onto the second row. Let's do Annika's sire, Usko. Usko's own name will go in the row 2; column A. His sire's name, Lotto, will go in row 2; column B. His dam's name, Katja, goes in row 2; column C.

So now the beginning of our Excel file is going to look like:

A Different Way to Save
Let's take a time-out here to do a SAVE-AS. First give your file a name. (I called mine "flock".) Don't hit save yet. The next part is important. Rather than just saving it as an XLS file (like Excel usually does), you need to save it as a CSV file. This stands for "Comma Separated Value" and it tells the computer to act as if these items were separated by commas, which is what FSpeed wants. So do a SAVE-AS and then use the pull down menu next to "SAVE AS TYPE" and pick CSV. Easy as pie. Now here is the only hard thing. Every time you do a save, you need to make it a SAVE-AS, not just a regular save or it will try to switch it back to an XLS file and we don't want that. It may even ask you if you are sure you want an CSV file. (You do!)

To continue on with entering our data, Row 3 will have Lumi - Timmy (her sire) - Wendy2 (her dam) Row 4, I went back and the parents for Usko's sire Lotto - 30013lassi (Lotto's sire) - Ninna (Lotto's dam). There were multiple sheep named Lassi in these pedigrees, so I used his number and name together for his ID. (Maybe this is a popular name in Finland?) So now our Excel file looks like this:

Clear as mud? Actually, all you need to do is go through the pedigree of each sheep, then list the sheep itself in column A, the sire in column B and the dam in column C. So do that for all of your sheep and each of their ancestors. If you don't know an ancestor, just leave that column blank. Sometimes there are blank spaces on the FBA pedigrees. That doesn't mean that the parentage is unknown, just that the sheep was registred prior to computerization of the FBA studbook. You can pay the Milo, IA office extra to look this up for you, but these are going to be more distant ancestors so it probably isn't worth the money.

Eventually, the data entry will start to get easier. For example, my sheep Uma and Katja are littermates. So once I entered the pedigree for Uma, I only had to type one line for Katja. I just entered a line with Katja - Eino - Rowan. The list already has all of Eino's ancestors and Rowan's ancestors up above under Uma's info. I don't have to type that again. (This will make you increasingly happy as you get further down in the list!) And remember to save periodically as a CSV file.

Instructions using Notepad:

Open Notepad by clicking on the blue icon or shortcut. If you don't have one, then go to the Start menu in the lower left of your computer screen. Go to All Programs > Accessories > Notepad. You are going enter each of your sheep and each of their ancestors - one per line - just as in the Excel instructions above. Since you don't have those handy built-in columns, you are going to hit the TAB key (far left, second row of your keyboard) between each sheep. So it will look like:

The spaces between the names are made by the TAB key.

Now we are going to go to SAVE-AS, give it a name and save it as a text (TXT) file. Notepad wants to save everything as a TXT file anyway. so after you name it, you can just hit SAVE for all additional saves.

Using FSpeed:

Open FSpeed by either:

It will first open a window that tells you that you can purchase a fancier version of FSpeed at their website. Unless you wish to do that right now, just hit "OK" and move on.

After FSpeed is open, you are going to Open the "flock" file that you just made through FSpeed. Go to File > Open > "flock.csv" (or "flock.txt).

At the upper left, it gives you a choice of #G, this is the number of generations you will use to do your calculations. I set this at 10, which is the highest it will go. Even though our FBA pedigrees only list 5 generations, in some cases I own the sheep's grandparents. If I have listed the grandparent's pedigrees in my records, that gives me 7 generations in that case.

What Does it All Mean?

Once the file is opened it will tell you: The sheep, sire, dam, # of siblings, # of offspring and F%. The F% is the coefficient of inbreeding. Here it is listed as a percentage rather than a decimal. So it might tell you that F% = 12.5%. (This is the same as .125 listed as a decimal.) The parents of this sheep are first cousins. Usually, you will want to keep the numbers under F% at 12.5% (.125) or smaller.

So, could you buy a ram from me and breed him to your ewes? The program doesn't know if a sheep is real or not. So once you have your TXT or CSV file, you can add a theoretical sheep. (You can delete it later.) My new theoretical litter is going to be called "test1". It produced by breeding the ram you might buy from me "Ramses" to your ewe "Fluffy". We will say that "Ramses" is out of Bo x Mara. So you will add the following lines to your "flock" file.

And so forth...

Finding Pedigrees

All of the pedigrees of my sheep are on my webpage. Just go to the sheep's individual page and click on the link for pedigree or use the links below.

Ewes

Rams

"Frozen" rams

Last update: March 16, 2008

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