dun - breeding for dun

evolen · Post by **evolen** » Tue Jul 13, 2004 1:14 pm

dear members,
may it possible to breed a dun colored calf out of red and black cows?

regards from switzerland again

Duncan MacIntyre · Post by **Duncan MacIntyre** » Tue Jul 13, 2004 9:15 pm

I am not a geneticist so I hope someone will correct this if I do not get it right. The Dun gene works as a recessive gene affecting the expression of black - so a Dexter will only be dun if it carries a dun gene from each parent. If both are dun, 100% of offspring will be dun. If one parent is dun and one is black carrying dun, 50% will be dun. If both parents are black and both carry dun, then 25% of offspring will be dun, 50% will be black carrying dun, and 25% will be black not carrying dun. The issue of dun in relation to red I am afraid I do not fully understand - I would assume that a red may carry the dun gene but will be unable to show this, but may pass it on to offspring, who may pass it to second generation which will show dun if they are homozygous dun. There have been opinoons in the past which say that red and dun mixed may give peculiar colours including creamy colour but I have never seen such a thing. Has anyone seen this? I am currently using a dun bull and have a red cow so I may find out.

Duncan

Kathleen · Post by **Kathleen** » Wed Jul 14, 2004 1:10 am

Duncan's post is correct... yes a 'dun' is basically a black animal which is homozygous for the recessive dun/brown gene (the colour genes for dun/brown and those for black/wild/red are located at different positions) ...so if you mate dun to dun then -yes- you do get a 100% dun _BUT_ if the animal is red and not black then you can not see that it is dun because it just looks red... the reason for this is that the brown/dun gene does not affect the colour of the reds as it does the blacks... (and while I have not been given any explanation for this ...it is my oppinion that it may have something to do with the two different chemicals which are responsible for the red and black colourations...)
As to 'creamy' dexters from reds X dun ...from what I have been told and from the pictures I have seen this has no basis in fact ... basically because the dun/brown gene has no dillution affect on reds ... It is still a mystery why there are different shades of dun ... and the only logical explanation is that the shade of black underneath are 'different' and/or there are other genes affecting the power of the dun gene.

So Evolen the answer is that yes you can breed a dun calf from the mating of a red and a black.

All the best
Kathleen.