dun to dun

nz dexter · Post by **nz dexter** » Thu Dec 13, 2007 10:27 am

Does dun to dun garantee a dun calf. The genetics behind the parents are Sire one black parent and one dun parent the Dam both black parents.

Also the same bull (1 dun parent and 1 black parent) over black cows (with black parents maybe 1 or 2 reds about 4 generations ago) what are the colour probabilities?

Sylvia · Post by **Sylvia** » Thu Dec 13, 2007 11:40 am

With absolutely no knowledge of genetics at all I'd say NO. Especially if you are hoping for a dun calf. But I'm sure Kirk will give you the definitive answer, bless him, when he has time.

Duncan MacIntyre · Post by **Duncan MacIntyre** » Thu Dec 13, 2007 2:53 pm

I am sure Kirk will confirm this in more correct terminology.

The dun parents carry two genes allowing dun, so will only produce dun calves unless red is interfering in the background.

With one parent dun and the other black carrying dun, 50% of calves dun.

With the dun bull and black cow not carrying dun, no dun calves but 50% will carry dun but not show it.

Duncan

welshdexterboy · Post by **welshdexterboy** » Fri Dec 14, 2007 12:40 am

I dun know either Sylvia :D

nz dexter · Post by **nz dexter** » Fri Dec 14, 2007 2:20 am

Now that is confusing. Is it like the recesive gene for humans ie blue eyes or red hair. So with my two black parents, they obviously carry the dun gene. Yes it shows in their pedigree, but some distance back!! I also got a bull (steer) also that was dun so 2 out of 7 were dun out of my first crop (all black parents) and none in the second crop. The previous owner of the bull used the bull prolifically and never had a dun. Interesting as the dams of the dun calves are mother and daughter.

Someone also stated about the red gene, how does this affect things is is dominent.

Broomcroft · Post by **Broomcroft** » Fri Dec 14, 2007 8:39 am

There is a topic from about 6-9 months ago called simply 'dun' that is full of very detailed info, if my memory serves me well. It is worth reading and may answer all your questions (possibly?).

The one you want was started May 30 2007 and has about 1200 viewings so you get the right one.

Edited By Broomcroft on 1197618212

Kirk- Cascade Herd US · Tue Dec 18, 2007 8:28 am

A dun Dexter really is a black Dexter with two recessive genes at a different location (the Brown "B" locus) that interfere with the completion of the black pigment that is called for by the dominant black (ED) genes at the E locus. So a black animal is ED/ED (homozygous black) or ED/E+ (black carrying wild-type red) or ED/Ee (black carrying true red). A dun animal must be one of those three types of black and also must also have two recessive "browning" genes at the B locus - written as Bb/Bb.

Here are all the possible genotypes of dun X dun and the resulting probabilities for calves:

ED/ED Bb/Bb X ED/ED Bb/Bb = 100% dun calves
ED/ED Bb/Bb X ED/Ee Bb/Bb = 100% dun calves
ED/ED Bb/Bb X ED/E+ Bb/Bb = 100% dun calves
ED/E+ Bb/Bb X ED/E+ Bb/Bb = 75% dun calves, 25% red calves
ED/E+ Bb/Bb X ED/Ee Bb/Bb = 75% dun calves, 25% red calves
ED/Ee Bb/Bb X ED/Ee Bb/Bb = 75% dun calves, 25% red calves

Kirk
www.cascademeadowsfarm.com

Edited By Kirk- Cascade Herd US on 1197963028