TB's and Arabians usually cross nicely to heavy mares, to produce a more refined baby. TB to keep the height, or Arabian to breed it down some. Some warmbloods will also refine their foals (although the one I knew of that did it consistently was actually Trakehner/Anglo Arabian) with the added benefit of adding some breeding that was bred to perform in English disciplines, thus adding some value (note, some, not a lot) to the foal.
This foal would likely be a grade, unless there is a sport horse registry that is based on type more than actual breeding. Grades don't sell for much, in fact I know of people who are literally having to GIVE their grades away. In fact the economy is so rubbish, even quality, registered foals aren't selling very well. Several of my state's top warmblood breeders have closed down, and the rest are severely cutting back on the numbers they're producing. Prices are down, sales rates are WAY down. It's a buyer's market.
You may not intend to sell this foal but you can't see the future, you can't know that you're going to be financially able to properly care for it. For the foal's sake, breed to something that will gain you a BREED registry, and if nothing that will refine the foal will allow a partbred registration, then don't breed at all. If it CAN be registered, get it registered. If it's only in the planning phase, put steps in place to ENSURE it can be registered.
I'm not telling you what to do with your mare, of course, just asking that you consider the value (and, following, chances of a good life - foals worth $$$ have a better chance of ending up in a knowledgeable home) of any resulting foal :)
And, when it comes to choosing stallions, consider your mare's conformational faults and ensure you breed to something that is exceptional in those areas. Consider your mare's conformational strengths, and ensure that she doesn't have any faults in areas where the stallion is not as strong. If you don't know about conformation - ask us! HF has some real experts.
EDIT; when crossing heavy to light, always ALWAYS ALWAYS cross blood over bone - or, in more simple terms, the lighter horse the stud, the heavier one the mare. Horses that are crossed bone over blood seem to have more of a likelihood of turning out fugly than those crossed blood over bone. We used to have a breeder in our state who bred some of the best Clydesdale-cross sporthorses in the country, one of which is now competing at CCI** in eventing, and in her 30+ years of breeding them, she had consistent great results with a lighter stallion and heavier mares. Sadly the GFC forced her to shut down her breeding operation, which is a **** shame because I would have LOVED one of her horses. There is some Appy blood in the two star horse, but not much - just enough to give him spots! Oddly, the colts from that mare and stallion are all spotted, and the fillies are all solid. If you're curious, Google his name - GeeJay Jackson :)
Last edited by blue eyed pony; 08-04-2012 at 01:56 PM.