Dexter calf colouration

[Dexter]

My 3 week old dexter calf looks black, but in the sun has a lot of brown/reddish hair in the coat. I noticed this when he initially dried off. If anything he's getting a bit more brown.
Both parents are PB dexters, mom's red and dad's a dun.

At what point can I be sure of his final colouration? Thanks.

[Karin L]

I'd say when he's about a year old...even then they can still keep changing until they reach maturity.

[LizD]

Hi 'Dexter' Take a look at the 'eyeliner' and tongue and gums of your Dexter calf, if they are a café au lait colour then the calf is dun but if they are black or charcoal then the calf is black, carriying red and dun, I would guess. We know that genetically a dun dexter is carrying black and black is dominant to red so unless you know that your male was also a red carrier or the dam a dun carrier, likely he passed the black gene. While I have heard of a case where a 'seal' brown coloured dexter turned out to be a dun, usually red or dun is quite different from black, even at birth. But checking the gums etc will tell you that. It is not unusual for the undercoat of a calf and even an adult to have brown or reddish tinge. Hope this helps, L

[randiliana]

Depends what color of Dun the sire was. A greyish dun or a tannish dun? Dun is a dominant gene, so if he's dun, he should exhibit it. Red is recessive.

My thoughts are (without knowing all the facts) that the sire was a grey dun which means that he has a black base coat, and that the bull was Hetero for the dun gene. The dam is red, so is not carrying the dun gene, or the black gene. So what I believe is that the sire passed on the black gene, didn't pass on the dun gene. The dam passed on the red gene, so what you have is a hetero black calf. He will probably darken as he ages.

[LizD]

Hi Randilana sort of, but that's not exactly how colour in Dexters work. Dun is actually a mutation that works on the black gene and carried at a different locus in Dexters, which is unique in the the bovine world. There MUST be at least one black gene at the colour locus, where there also could be a red gene. The mutation for dun is recessive if hetrozygous and the animal would appear black or red (if it didn't carry black). It must be homozygous and it MUST have a coresponding black gene at the other locus in order for it to work. In other words a dun dexter could be thought of as a black dexter whose colour was mutated dun. A red Dexter MAY carry the dun gene, may even be homozygous for the dun gene but it will still look red. If it carried a black gene it would look black or if it was homozygous for the dun gene it would look dun, but could still carry a red gene with the black. Therefore the dam COULD be carrying dun, even homozygous for dun, but not a black gene. The sire MUST be carrying black and MIGHT even be carrying red but MUST be homozygous for dun if he appears dun. So the calf in this case must have inherited a red gene from the dam and must have inherited a dun gene from the sire but also it inherited a black gene from the sire which makes it look black but still carrying red and dun. Clear as mud, eh? Liz