Last year I got 3 out of 4 and the one that didn't settle was at least partially because of operator error. If an animal doesn't settle the first time I always try to get them on the next natural heat. After that it depends, if it is a heifer and you trust your bull to breed her I would go ahead and put her out. If not then I would keep AI'in her at least one more time before you decide to sell her.