I weaned my calves 45 days ago, and they are in the lot now. I just noticed a few days ago that 3 of them out of 103, have a hump on their back. Like a hunch back. It is well centered on their spine even with the ribs. The calves act and eat like the rest. All 3 of them are steers. Is it something they are lacking in their diet, or genetic? Or what is going on?