I have been leasing a Trakehner X TB mare for some time and may be purchasing her at the end of the summer, she is 13 years old and is making huge progressions in her training and handling everyday. She is by Prince of Prussia (by Carino approved ATA, AWR, CTHS, CSHA and CWHBA) a BRINDLE bay and she is registered ATA and CTA, which makes me motivated to pass on her genes as well. (just love to see what color the foal is). She has great movement and her siblings all have been very successful dressage and sporthorses and she has done some hunters + lower level eventing. But, is she to old to breed (she has never been bred before) - I understand the factors such as health, attitude and stallion choice but does she seem to old to breed. A friend of mine said she was "getting" there and should be bred soon for safety reasons due to her age - but I would never rush it. It is very hypothetical anyway but I just wanted some opinions. (And if anyone knows of some great Trakehner stallions ;) Thanks for your time!

The older she gets, the more risky the pregnancy.  And because she is a maiden mare, the risk increases even more.  You're taking a risk any time you breed a mare, though, because complications can arise any time.  My mare had her first foal at 10, and she was fine.  If you do plan to breed her, I second doing it sooner than later for the health of the mare and I also recommend working with an experienced breeder and vet.

 Where are the pictures?  She sounds beautiful!

If it was my horse, I wouldn't do it, especially if she is your riding horse.  The risk involved in pregnancy and foaling, not to mention the expense even if everything goes perfectly, is too great.  If you want a young horse of a fun colour, with nice movement, they are not hard to come by right now at zero risk to your lovely mare, just start shopping!

I wouldn't do it... my Walker mare was about that age when I considered breeding her (she's a maiden as well).  I decided the risks were just too high and I knew I would never, ever forgive myself if something happened to her during pregnancy or foaling.  I ended up adopting a rescue filly instead.

Oh, and it's hard to tell if your mare would pass the brindle color on to a foal.  Brindle color in horses is sometimes caused by a sabino or roan factor, but also sometimes the horse is a "chimera".  Which means in basic terms, when she was a fertilized ova there was a twin, and the two ovum merged together to form one fetus.  This turns out a horse with two different sets of DNA.  The hair may test one way, and ova/sperm can test another.  Pretty cool, huh? :)  Here's a neat website about bindle colored horses: http://www.brindlehorses.com/brindlehos/index.htm

I'm sure you probably could breed her with no trouble, but like everyone else said (and I've been shopping) people are just giving away super weanlings and yearlings and you could get the color, breed, gender, whatever you want.  Probably for cheaper than even dealing with the vet and the fee and everything (and the late nights of panic).  But it is super fun, and I can definitely commiserate with wanting to do the whole process yourself.  That's not a bad age, I asked a vet once when I was in a similiar situation, and he said it just depends on the health of the horse, but some people (and Im not endorsing this) breed mares well into their 20s.

 The statements about breeding the horse that you depend on to ride are honest concerns. A lady I know, bred her mare (a very nice TB, had a great foal) had an injury which has caused ongoing lameness. She is not ridable. 

Plus, consider that there are already many, many nice horses out there just as you described wanting as a result of a breeding. The cost of breeding to a quality stallion, vet bills, etc. - well, you might as well go buy a young horse.

 Consider also that there are thousands of horses that end up unwanted, neglected, etc. Fewer people need to be breeding (in my opinion). Let's give good homes and lives to the ones already living, and if we breed, breed for a specific discipline and purpose, not just to have a foal. Where I live we also have hundreds of unwanted cats and dogs, because poeple think it's fun to let their pets have kittens and puppies.Many of these end up in shelters, abandoned, or euthanized.

Thanks everyone for the comments but once again I will state this is highly hypothetical, I just wanted opinions and I am very aware of the cost in breeding/raising/training young horses. I also know that are are so many unwanted horses in the country and that there are many young horses available.

Thanks for the site but I have also read-up and done a lot of research on the gene/color - I am very aware that it may not be possible to pass the gene on but I would still love to have a little version of mare mare no matter the color. Once again, hypothetical - I will not go on random comments but the opinions are nice - if I go through with this I will work closely my vet, trainer and breeders to make it as safe as possible and get their educated opinions as well.