Colour genetics- Chev?

[Horsesarelife]

One of the mares at our yard has just gone to stud. EVeryone is wondering what colour the foal is going to be/ could be.

The mare is a cob of completely unknown breeding but is chestnut with 2 white socks behind, and she has a white splash on her belly- does that make her a sabino?
She is as she gets older (shes about 12 now) she is looking a bit roany all over with white hairs mixed in with the red but I dont think she had this a few years ago when I first met her.

The stallion is a national hunt horse, honeybrook siren.

http://www.endhousestud.co.uk/frameset.htm

Don't know if anyone will be able to make anything of it but thought I would ask anyway

thanks

[fiesty_filly]

There is no way of telling exactly what colour the foal will be. With the sire bay and the dam chestnut you will most likely get a chestnut as I believe that it is the most dominant gene (though correct me if I'm worng, bay might be). Without knowing the mares breeding it is hard to say whether or not she would pass down the paint colouring. You are most likely to get a solid chestnut, but the possibilties are endless!

[Mehitabel]

chestnut is recessive - they have to have one chestnut gene passed on from each parent. so mum has 2 chestnut genes and will definitely pass one on to baby.

dad - well, it depends what colour his parent are and whether he has 2 bay genes (he must have at least one, to be bay) or one bay and one chestnut, for example.

[chev]

Foal will be bay, black or chestnut, depending on several factors. Like Mehitabel says, mum can only pass on chestnut, so baby will have at least on chestnut gene. Mum might also have bay to pass on - the bay modifier is only visible on black based horses, so she could carry it without it being seen.

Dad has at least one bay gene, and at least one black - he could have two black or one black and one chestnut.

So - if dad passes on a black gene, foal will have a black base. If foal gets dad's bay gene as well, or one from mum we don't know about, it'll be bay, not black. If neither parent passes on bay though it would be black.

If dad has a chestnut gene to pass on, and baby gets that, it'll be chestnut, even if it gets bay as well.

It may or may not show sabino - sabino expresses best on chestnut coats, but can show up as a lip spot and socks, or roaning, or a wide blaze, or even big white splashes extending up the body, or any combination of those factors.