Color factor testing is beneficial because it tells you things that you don't know about the horse or prooves the horse is or is not a certain color, it gives you a better idea of what colors that horse can produce in it's foals and with that information you can breed to horses of certain colors which gives you a better chance of getting a certain color.
For example, if you have a chestnut/sorrel horse that has one or two bay parents, you could test it for Agouti. Agouti is the gene that controls Bay. Because the horse is chestnut it could have Agouti and not show it as Agouti only effects black pigment, chestnut horses only have red pigment. If the chestnut horse has Agouti it can reproduce bay offspring when bred to a horse that is black. If the chestnut has two bay parents it could even be homozygous for bay, meaning every foal it ever produces will have Agouti and those that are black based will be bay.
More examples; It is often difficult to tell if a horse that is a double Cream dilute is a Cremello, Perlino or Smoky Black because the three colors can be very similar, red factor & Agouti testing clears up any confusion. True grey horses or max white horses can be another tough one but by taking advantage of the color testing available you can have much better idea of what that horse can reproduce color-wise. The list of what color testing can prove goes on and on....
And of course there is the one color test that is very important if the horse is pinto and/or has pinto background - the LWO test. When two LWO positive horses are bred there is a 25% chance of the foal being a Lethal White.
Sometimes certain color tests for certain horses are not necessary. There wouldn't be any need to red factor test a horse that is chestnut (
truly chestnut not a silver bay, etc.), or if you have a horse that is bay, really no need for any tests on this one unless you wanted to know if it was heterozygous or homozygous for red factor. With colors like these the color testing isn't really nessesary unless you want to know
right now - you can just sit back and wait to see what color foals are produced rather than spend the money on a color test. Heck I waited for two foal crops to see what color one of our stallions was rather than spend the money on getting him tested.
I don't know the backgrounds on any of your horses or what they've produced so this is just my opinion based on the photos...
Harley & Levi - if either of these horses has
two bay/bay based parents you could get them tested for Agouti to see if they are heterozygous or homozygous. Because they are physically bay/bay based we already know they are at least heterozygous for Agouti. If either only has one bay/bay based parent don't bother w/ the test.
Sam - I would LWO test this guy.
Bay B - According to the AMHA studbook both parents are bay so I would test her for Agouti.
Poca - test for LWO.
Shortycake - LWO test & if either or both parents are bay/bay based, Agouti test
For color testing I always recommend UC Davis because they are a reputable lab and if they make a mistake they admit it and redo it for no charge - there are other labs that can't say they do that.
http://vgl.ucdavis.edu/service/horse/coatcolor.html
They do red factor & Agouti testing as one test for $50, after that any additional tests (on the same horse) are $25. LWO tests are $25 and Cream tests are $25.
There is another lab that allowed itself to be blind tested against UC Davis and scored 100% but I can't remember their name right now. I'll look for it and post it later, I believe their testing is $25 per test also.
Edited: OK here is the other lab: Pet DNA Services of AZ -
http://www.petdnaservicesaz.com/Equine.html
