My husband and I have started raising Jersey Calves, we started with 6 as of today we are down to 3. When we first got them (they are number 5-10) #6 was our weakest and we thought he would die with in the first few days, however we did nurse him back to health, it had been a few days and #10 started looking sick and they all started to scour. We cut back on milk replacer and started electrolytes, almost over night #10 went from bad to worse and my husband put him down as he couldn't even lift his head. Then #8 started getting even worse, so we cut milk a lil more and gave more electrolytes, he was even given Draxxin. This was the point when we found two dead birds floating in our water supply. We assumed that this had so far played a huge part in what was wrong with the calves. We started getting fresh water to bring to them from a new supply and slowly #8 started moving more and seemed to be getting strong but as he was getting better we noticed that #5 was starting to get weaker. So we push electrolytes and with in a day or two they all seemed to be doing a lot better. Then two days ago my hasband checked on them on his way home from work and they were all up and great. When we went back in a hour to feed #5 was down and unable to get up with in the hour that we were there he went from weak to convulsing and so we put him down. All the others seemed great since then tails wagging, ears up, chasing us for food, eating pellets and drinking free choice water, and scours were gone. So besides just not seeming to put weight on they all seemed to be doing a great abit better. Until today, when my husband went out for morning feed time #8 was dead. I do not understand what is going on. How are they going from what seems so well to dead in as little as a few hours. Please anyone with advice help. All advice is appreciated.