Color/Genetics Questions!

Ok so after breeding my mare last spring I became really interested in Equine Color Genetics, though I don't know a whole lot YET lol I still find it very interesting! So my first question is how can people tell the status of a horse without testing? Can you tell anything about my mare? She is Dun, has had a Grullo foal (stallion was a haflinger) her mother was a Grullo and her father was a Buckskin Overo.
My other question is about Spice's (my mare) Dam. Her name is Ben Marks "Lady" (AQHA) and was a Grullo. She has had at least 10 foals... at least, and not one of them was sorrel/chestnut, or bay. She has had everything under the sun, Palminos, Duns, Grullos ect... Is this sheer luck? Or does color genetics play a roll here? Oh and Lady was bred to a variety of colors including bays and chestnuts/sorrels.

Some horses you know what certain statuses are by looking at them and their pedigree.

For the most part though, no there is no real sure way to tell whether a horse is homozygous or heterozygous for genes.

There are some you know for sure the status of one set of genes by looking at them (such as red based horses like chestnuts/sorrels are always ee, and cremelos are always ee CRCR).

Best advice on wanting to know what a horse will produce? Test it and know the genetic status of the horse it is being or will potentially be bred to.

Well I am no expert, lol but I do know some. She is a grulla, which means she is a black horse with the dun modifier. Are you sure her sire was a buckskin overo(tested) or is it possible he was a dun overo? That's the thing about genetics, even with a complete family history you can't always tell for sure without genetic testing. For her to have a grullo foal, it is likely she is homozygous for black because both a grulla and a buckskin have a base coat color of black, but nothing is for certain, she could still have managed to get a recessive red from one of the parents. As I am working this out in my mind,lol, a "zebra dun" (the ones that look like a buckskin) is actually a bay horse with dun. A bay is a black horse with the agouti modifier that changes the body color but not mane and tail or points(typically). She would have given a black gene no matter what, which is dominant over red and we know the Halffie had red. It IS possible however, that she does indeed have a red gene and it was just the luck of the draw.

If her mother has had a palomino foal, correct me if I am wrong people, but I believe that means she has to have a recessive red gene hiding behind the black and the dun modifier. If not, she would have given baby a black no matter what and black is dominant over recessive red. A palomino is a red horse with a dilute gene.

The short of it is, genetics play a HUGE part in color, and we are still learning new things about color genetics. I am like you, I find it fascinating, but it will be a long time before I understand it completely,lol. And don't EVEN get started on the LP(appy) genes, I get totally lost,lol.

Thanks NdAppy! I just though it was interesting that Lady never produced a "red" foal. She couldn't be homozygous for the Dun gene because she has had palominos correct? Also because she only had on Dun parent she couldn't be Homozygous Dun Anyways. Her sire was a palomino, and her mothers color was unknown, but im assuming dun considering Lady is a Grullo. Correct me if im wrong but since she is a Grullo she doesn't carry a cream gene right? So how come she never threw "red" babies even when bred to a "red" stallion?

She did produce a red foal though. The palomino is red based. All horses are either red or black. Everything else is a modification of those two base coats.

[QUOTE=NdAppy;1302235]She did produce a red foal though. The palomino is red based. All horses are either red or black. Everything else is a modification of those two base coats.[/QUOT

Oh ok!!!and the foal must of gotten the cream from its sire... ok!!! Lol

Spice is A Bay Dun/Zebra Dun (same thing) Her Dam... Lady was the Grulla, and Spices Sire... Scooter was FOR SURE a Buckskin Overo. If it means anything Ladys (the Grulla) Sire was a Palamino. And Scooters Sire was a Black/Overo

What were Lady's sire and dam?

I'd be willing to bet that your mare is a brown dun and not a bay dun.

Ladys Sire was a Palomino, and the Dam I don't know. Wouldnt she have to be a Dun or Grulla? Her Name was "Two D Adair" By "Two D Two" out of "Pony Adair"

Out of curiosity why do you think she is a brown dun?