Iodine will only do good in the first few hours. After that the infection has already started its path upward. The first few signs are a cord that does not dry up and go away. After that the area where the cord is will look larger than normal and as they move will look weighted as it swings. You can catch the calf and feel swelling and puffiness at that point. If I were buying them I would probably still spray the cord with iodine anyway when I got them. I have started to use a Vetericyn product for umbilical cords and like it better then iodine. My vet told me iodine sometimes will make a cord stay wet longer and then not dry up and this does not seem to do that. The calves I have had trouble with are the calves that do not move alot and stay hid out. They are laying on the cord more and it stays wet. As long as that cord is wet there is a path for infection. I have had a calf or two several years ago that I caught and it had a small infection starting in the cord area and I took my knife and got the end of the cord out that was infected and then injected pen and flushed with hydrogen peroxide and didnt have any more trouble. If you get to them early you have a chance but let it get to the joints and it is bad. I had one calf a few years ago that I treated for a period of time and thought it was out of the woods and it was growing and doing well and about 3 months old. I just found it dead one day and I opened it at the navel and I could see how its intestines were discolored and it went on up higher in its body. My vet said it probably went to the heart. Sorry for the long sermon.