I have used the Quiet Wean tags for the last 5 years. I wouldn't wean a calf without them. I have had one calf that figured out how to nurse after a week, but just one. Occasionally, one will lose one and I have to put in a second one and my current herd bull lost two when he was weaned. Really helps to soak them in a bucket of hot water before inserting them. They are much more pliable warmed up. If you remove them one day and separate the calf and cow, bawling on both ends is all over by noon the next day and it is pretty mild fussing at best compared to weaning without the tags.