We had to have the vet come and pull a MUCH ANTICIPATED calf from my son's best heifer yesterday at about 6 pm. The calf was very large. She is alert and when we tie her mama up and put the calf's head up to the teats she latches right on and goes to town sucking. However, it has been 12 hours and still not putting it all together to stand. It seems like the problem is in her back legs, she trys but just flops back down. Her legs and feet appear perfectly formed and normal. How long to wait before we just give up and count her as a loss? I DO NOT want her to lay out there and suffer in anyway. Any opinions/suggestions would be welcome. I am calling the vet as soon as 7:30 gets here. Just FYI she is out of a Tyson heifer and a very low birthweight Brangus bull. I think that the mama is just too small.