Friday, April 08, 2011

Sheep Geekiness

Still waiting for lambs. It appears that my observations were not correct. Sometimes ewes have what is called a 'false heat' and then have a proper heat about 10 days later. If that is correct, then Eirina will be the 15th and Lifa the 18th. In the meantime, Draga seems to be in labour. Isn't she huge? Last night it was below freezing so I set my alarm for every two hours to get up and check on her. She isolated herself from the rest of the flock and her bulk seems to have shifted back. She is even more enormous now, if that is possible.

For bedtime reading I have been reading the lambing sections in all my sheep books. Last night I was reading Ron Parker's "The Sheep Book". I learned that last night when the milk bag is hot to the touch, lambing is less than 36 hours away. So this morning I went out and touched Draga, Eirina and Lifa's udders. Only Draga's is hot to the touch. So there, is your first bit of sheep birthing trivia.

Here's your next bit. The size of the milk bag is in part due to the ram because the hormones for bag development comes from hormones from the lamb inside. Interesting because I made sure that Renauld came from a good milky mother with a large milk bag. I thought it would mean that he would throw good milky daughters. Maybe it will have some effect but all my ewes make large bags and are very good milky mothers. So the size of lambs a ram throws is not only determined by the genetics of structure but also by the effect the lamb's hormones have on milk production. Fascinating, eh?

But here is the real geekiness. Awhile ago when apparently I had nothing better to do... I decided to try to decode my flock's colour genetics. I found this great article and this one, too. Together I was able to make sense of this somewhat complicated thing. So here's what I learned. There are basically 3 sets of genes that control the colour and patterns of a sheep. The first (factor B) is the base colour. All sheep come in one of two colours - black or brown. Brown is recessive. And white is not a colour, it is a pattern that is dominant over all other genes. But I'm getting ahead of myself.

The next is factor A which is the gene for patterning. There are 6 different pattern possibilities. Solid pattern is the most recessive and white pattern is the most dominant. I learned studying this that Draga does not have the badger face gene. She has the spotting gene and I think she also has the mouflon gene. Mouflon is the opposite of badger face. Mouflon is a dark sheep with a white belly and stripe going up to the bottom of the jaw. It is hard to tell exactly because of her spots. But I am pretty sure she is both spotted and mouflon. But spots are not a pattern gene.

Spotting or not spotting is the third gene called factor S. Spotting is recessive to no spotting.

There are also some other minor genes that affect colour. One is the Phaeomelanin Factor. This is a gene that "allows the wool follicle to produce a pigment called phaeomelanin which has been described as tan, yellow or sometimes red. It has been seen most frequently on the head, legs and tail of white sheep."

So then I set about decoding my sheep's genes. ( I told you this was a really geeky post... still reading?)

Renauld was the easiest. For one thing, I get to see several examples of his genetics every year. Also he has several recessive traits which eliminates a lot. This is what I know about him:
Factor B black brown
Factor A solid solid
Factor S no spotting spotting

Because Renauld is a registered ram, I could even go onto the Canadian registry and get really geeky. I knew he must have a gene for brown because he has had brown lambs. If he was black/black, he would only have black lambs. And sure enough, on the registry, I discovered his mother was brown. I knew he must have the spotting gene because he had two spotted lambs last year with Draga. And obviously he has two genes for solid because that is recessive and he is solid.

Next up: Brida, my brown ewe.
Factor B brown brown
Factor A solid solid
Factor S no spotting ?

If she ever has a spotted lamb, then I will know she has the spotting gene. If she does carry the spotting gene, there is only a 1 in 4 chance she will have a spotted lamb.

Next up: Draga, my spotted ewe
Factor B black ?
Factor A mouflon? solid
Factor S spotting spotting

So far Draga has had 3 lambs (stillborn the first year) and they have all had the base colour of black. I know Draga's mom was solid black. But she could possibly carry a brown gene, too. I will know if she ever has a brown lamb.

Next up: Eirina, my white ewe
Factor B ? ?
Factor A white ?
Factor S ? ?

I know both her mother and father were white. So there is a real possibility that her two pattern genes are both white which means I will never find out what is underneath that because those are dominant over everything else. So far she has had one white lamb. I will find out more sometime soon...

And last: Lifa, Eirina's daughter
Factor B ? ?
Factor A white solid
Factor S ? ?

Because her father is Renauld, I know that she has only one gene for the white pattern and must have one for solid. There is a 50/50 chance for her to have a coloured lamb and that will tell me what colour(s) she has hiding under the white. And that will also give me a clue to what is under Eirina's white, too.

Both Eirina and Lifa have the phaeomelanin factor. The both have a rust coloured band across the back of their necks, rust legs and a little rust coloured tail.


Beth-a-knee said...

I have to admit that when you got into the individual sheep's decoding of genetics I skipped quite a bit of that. I'm sure it would be more interesting if I had any sheep. Good luck with the lambing!

Sarah-Lynn said...

wow. Genetics are interesting. You really do have some gene-geekiness in you! You're always breaking down who got what feature from who in our family, so the fact that you are interesting in your sheep's genes, doesn't surprise me. How fitting that it's your middle name. Your sheep are so lucky to have such a loving owner.

eryn. said...

hahaha... i thought it was interesting. maybe finding geeky genetics interesting is in my genes?