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What tests do I need to do? Tobiano mare

Hi Everyone, I'm very new to here :) I have a tobiano mare that I am considering breeding with. I don't understand much (!) about breeding with coloured horses so I want to learn as much as I can so as I can research the best stallion for her. Could someone please explain homozygous to me and its opposite? Can't spell it! What if any, tests do I need to do on mare? There will be more questions as we go, but that's probably a start! Thank you

Third Peppermint Sat, 03/30/2013 - 21:07

If a horse is homozygous for tobiano it has two copies of the gene that causes that pattern. If it is heterozygous is has only one copy. Since horses pass on only one of the two (can be either, that's random each time) if it only has one copy that means it has a 50% chance of passing on the gene, but if it's homozygous it has a 100% chance of passing on the gene.

As far as testing the mare - that depends what you're looking for. Bare minimum would be to test her for frame even if the horse doesn't look like she has it. If she tests positive for frame and you breed her to a stallion that also has frame (whether or not you can see it) there is a 25% chance that the foal she has will die soon after being born due to lethal white syndrome. Definitely NOT something you want to mess with. I'm not sure what else you want other than spotting so I can't say what else to test her for.

If you're aiming for color your best bet is to breed her to a stallion that is homozygous for a white pattern like tobiano. Either way that you take it I highly recommend making sure you can get the foal registered and you pick a stallion that has more than just color going for him. Excellent conformation that compliments the mare's and a good show record is a HUGE plus. You definitely don't want to breed to a loudly marked, but poor quality stallion because you could possibly end up with a slipped tobiano - that's a horse that genetically is tobiano, but looks "solid."

Lakey Sun, 03/31/2013 - 05:21

Thank you very much, you have explained it perfectly, understood it completely. The explanations on the net were too detailed, they all went over my head!

Confirmation will come before colour but I'll only look at tobiano stallions to increase my chance of a coloured foal. Ultimately I'm aiming to breed a foal that will be competitive in dressage, sensible temperament that hopefully stands out from the crowd a little. My mare is this, unfortunately she has done a serious tendon injury that isn't looking promising for a performance career.

My mare isn't registered, I don't have papers for her sire (paint) so would this affect registering the foal?

Thanks again

Third Peppermint Sun, 03/31/2013 - 10:10

Ah, if the mare isn't registered the foal can't be registered with APHA. Both parents need to be registered with APHA, AQHA, or the Jockey Club to be eligible. IF the horse comes out with a pattern that qualified you could possible register it with the Pinto Horse Association of America. I know there's a way to register a foal as half-Arabian, but Arabians don't have tobiano so you'd be out of luck getting a colored foal (actually just a 50% chance unless your mare is homozygous.) I think some warmblood breeds will allow a foal to be registered if they can pass inspection and there are warmblood stallions that are tobiano, even homozygous tobiano. I would definitely be really careful with this.

Lakey Sun, 03/31/2013 - 17:40

My mare is part Arab (dam) and warmblood sire (obviously crossed with a paint as he is tobiano).

I'll have her tested for the overo gene and whether she is homozygous or not. And when I look for a stallion ensure he is homozygous and preferably overo neg. if my mare is overo pos then he definitely needs to be neg.

I'm in Australia so I'd be looking at different registrations. I'll talk to my local societies.

Thanks.

rabbitsfizz Mon, 04/01/2013 - 12:18

There is no overo gene- do you mean LWO-AKA Frame?? Important to know as the lab will ask!
How much percentage of Arab blood does the have? There is a chance you could register the foal, not sure what registries Australia has....

rabbitsfizz Tue, 04/02/2013 - 13:03

Depending on the qualifications for Aus- you can register/should be able to register, the foal with the PBA registry......
I was only being picky because if you ask them to test for overo yu never know what you will get!!!