About a week ago we picked up 3 holstien calves from a dairy, 2 less than 12 hours old, one 3 days old. We fed colostrum for 3 days, then put them on a cow. After 2 days, one of the younger calves became very weak in the rear legs. After a day of that, he stopped eating, so we started tube feeding him. He started grunting and acting like he was in pain, and the weakness progressed to him not even trying to get up. He finally died a couple of days ago. Went out just a bit ago, and the other younger calf is getting wobbly in the rear legs. HELP!