If your calf has scours, raw eggs added to the milk replacer provides extra protein and is said to help firm up stool. Also mix in some Karo syrup. If your using electrolytes, do not feed it at the same feeding with the milk replacer.
We do this for scours. We usually start with electrolytes and one egg in full bottle, no milk replacer at first. We advance to about half milk replacer with electrolytes and egg until no more scours, then back to normal feedings. I think it works great.