Must carry red?

[tonhou]

I have these results from colour tests for a cow:
"Ed/Ed B/b - Animal is black, carries dun, cannot have red offspring."
My question is - if she is mated to a red bull and has a black calf, must that calf carry red?
Thanks

--Tony

[marion]

Yes

[Cascade Meadows Farm - Kirk]

Here's why

A red bull MUST have 2 red genes (E+ and/or e) and cannot have a black gene. Black (ED) is dominant over red, so black can't hide.

Each parent contributes one gene.

Your ED/ED cow MUST contribute an ED gene because that's all she has

The red bull MUST contribute a red gene (E+ or e) because that's all he has

[tonhou]

Thanks - especially for the explanation Kirk.

--Tony