A dun question

[karenp]

Sorry, I couldn't resist the pun

So, tell me if I have this right. To get a dun calf, the phenotype must be black, but the genotype can carry red, additionally they must by homozygous for dun. A dun bull that carries red bred to a black cow that carries red and dun could give you any of the tree colors?

[Deleted]

let me see if I can simplify for you. In answer to your last question yes that is right you could get all 3.

black and red exist on the same gene pair and black is dominate.
dunn exist in its own gene pair. but will not be expressed unless it would be an otherwise black animal.

so the only way to get a red animal is if you have 2 red genes.
the only way to get a dun animal is 2 dun genes on an otherwise black animal.
all other combinations will be black.

 

[rilie]

This spreadsheet calculator was posted on another Dexter forum and I've found it really helpful, though I warn you it takes a lot of playing around with it to figure it out (unless you already have a strong excel and genetics background). Once you figure it out it gives you an accurate percentage chance of getting a specific color. The beta casein portion is helpful too.

Dexter Cattle Sex Color A1A2 and Poll Calc.xlsx (20.6 KB)

[Donlin Stud]

Or you can have a red Dexter that has two dun genes - so had she received a black gene from just one of her parents, she would have been coloured dun.

We have two girls that are red in colour but are double dun.

BTW We have had more success in seeing dun coloured calves when the dun coloured parent does _not_ carry red.

Hence our two red coloured girls that carry double dun.

Our 2015 calf drop were all coloured black - but should have been a lovely mixture of red and dun as well as black................instead mother nature decided she was going to play a joke .