I usually disbud my calves at 3-4 weeks old simply because I feel they are old enough to deal with a little stress. Below are photos of the tool and steps that I use.
First trim away hair from the horn bud using scissors or clippers. Now you can clearly see the horn bud tip and darker horn bud color. I used to mark the bud tip with a colored marker to always see the target before the burn.
This is the iron I use for calves and goats (Rinehart X-30). Heat the iron until the hot end is cherry red.
Next secure your calf in some type manner. I use a miniature head catch.
Now burn the outside of the horn bud for 10 seconds, not a quick 10, a real ten seconds with moderate pressure. While burning rotate the hot iron in a circle pattern achieving a copper ring around the bud. I burn 5 seconds on one side, shift to the other side then back to the original side for the added five seconds and so on equaling 10 seconds each side. The photo will show the copper ring, the yellow color is a spray coating.
Spray with a anti-bacterial coating if desired.
Once completed release the calf and determine who need the nerve medicine the most, usually I do....Hope you enjoyed the thread....Topside