You are wading into a very deep pool but I would like to offer this as some consolation. Holstein cows are widely breed and kept in the US and they are doing fine. Now I know some people will bring up negative points about Holsteins but my point is that they have been breed in captivity much longer than snakes and for the most part are fine. Thats not to say that we won't find a corellation between piebaldism and some negative trait but guess what. Negative pop out of wild populations all the time. I would be much more concerned with kinking or wobbling in carmels and spiders respectavely.