Bay mare and stallion = chestnut foal?

[Shannon_Clover]

Bay mare and stallion = chestnut foal?
Is that correct?
I thought the foal would be bay like his parents or will the foal change colour?
Just curious. :)

[Mehitabel]

perfectly possible., chestnut is recessive, so the horse needs 2 copies of the gene to be chestnut. the bay parents will have one bay and one chestnut gene each, so they will be bay - but they have passed their chestnut genes to baby.

[skye06]

Agree with mehitabel. Possible but not set in stone genetics can be devious.

[Tangle]

Yep - agree with Mehitabel :).

All you know from the parents being bay is that they have at least one Black and at least one Agouti gene each - the Agouti gene restricting black to the points.

So, theoretically, you could get a black, bay or chestnut foal from two bay parents. If either parent has two black genes the foal would have to have a black base. If either parent has two agouti genes then the foal would be either bay or chestnut (depending on whether it received at least one black gene or not).

Hope that isn't too confusing :o

[Shiny McShine]

Some bay foals are born without distinctive dark points, so it's possible the foal could go bay as the adult coat comes through.

Chestnut is definitely possible from that combination, and if so would prove both parents to be heterozygous bays.

[chev]

Proves both parents to be hetreozyogous for black, not bayt.

Hetreozygous black - one black allele and one red (chestnut).

Both parents could have tw bay alleles and always poass bay on - but on a chestnut foal, you won't see it, because bay only alters a black base, not a red one.

So a chestnut can in fact be homozygous bay (have two bay alleles) and will still be chestnut visually... :)

[Miska]

My dads mare has just given birth to a light chestnut foal and both dam and sire are dark bay.

[Shiny McShine]

Proves both parents to be hetreozyogous for black, not bayt.

Hetreozygous black - one black allele and one red (chestnut).

Both parents could have tw bay alleles and always poass bay on - but on a chestnut foal, you won't see it, because bay only alters a black base, not a red one.

So a chestnut can in fact be homozygous bay (have two bay alleles) and will still be chestnut visually... :)

Yeah, that's what I meant. :D

[Lgd]

Chestnut is very good at hiding, as demonstrated by two of our 'family'.
George is chestnut from two bay parents. We didn't know the colour of his dam's parents but his sire is out of a chestnut mare by bay stallion. So expressed bay with the chestnut hidden, although he had a very metallic cast to his coat.

Peri is a grand-daughter of George's Mum - her own dam was bay by a bay stallion called Stephen Henri. Peri has the same sire as George, of all of his bay offspring from various mares she is the only one who has the metallic cast to her coat. She has just produced a gorgeous chestnut filly - the sire is chestnut so it was always a possibility if Peri was hiding the chestnut gene as we suspected.

The weirdest bit is that the filly has almost exactly the same white markings as her chestnut great-granddam.