I understand now. I would continue to give him the packaged colostrum for the first 24 hours, then switch to a good milk replacer - make sure it is milk by products, not soy, and is at least 20% fat and protein - in small quanities (say a pint or maybe 2) every 3-4 hours. In a couple of days, as his stomach becomes accustomed to a larger amount of milk, gradually increase the quantity/feeding and start cutting down the number of feedings. Watch him closely for possible scours and adjust the amount of milk replacer accordingly. If cutting back the milk solves the scours problem, wonderful, if not give him a double dose of a good scour medication for the initial dose, then go back to the regular dosage if need be. In about a week, start introducing a handful of calf starter or COB and a tiny bit of hay. You might have to put a little bit of the grain in his mouth to begin with, and you might not - it just depends on the calf. I'm going to catch flack for this, but I'm not a big believer in the gallon of milk replacer/day that is recommended. I try to raise my bottle calves like their mother would as much as possible, and I generally give mine 2 gallons/day because that is what most of our beef milk cows gave. This is how I do it, and I hope it helps.
PS You know about the water thing, but you may not know to keep a good mineral available for this baby, too. Calves as young as a week old will eat mineral. I put mine in a half-barrel crystal-x tub that is kept in the shelter (not barn) provided for the calf.