can't say I've seen this before. Picked up a group of 2 day olds from a new dairy (new to us anyway). Have had 3 of 20 come down with same thing...all at 7-10 days old. drinking fine morning feeding and then by the night feeding, laid out, wont get up, and kicking and thrashing like they've lost the use of their front or back legs. Not kicking stomach where you'd suspect abomasal bloat, but kicking like trying to get up but cant. only shots they get up to that age are a Multimin injection on arrival. Haven't seen this before and does seem to be isolated to a single group of calves.