With flame-clipping, hair on the cow's udder is removed with a propane torch using a cool flame. The flame is passed quickly under the udder to singe the hair off. It must be done correctly to remove hair thoroughly without burning the skin on the udder or teats.
Although the idea of running a flame around the udder of a valuable cow may seem foolish at first, flame-clipping udders is safe and very effective when done correctly. Many dairy producers have found flame-clipping to be easier than electric clipping, taking less investment in equipment and less effort. Because of this, they are more likely to flame udders on a regular basis throughout the winter, when they may not have used electric clippers.
Flame clipping can be done in the milking parlor or in the larger feeding area. It takes only a few seconds per cow and should be done every 4 to 5 weeks.
I wasn't aware of this until yesterday and I checked , its down here is NZ . From what I saw , some cows are in pain , when they are "flamed". It uses what they call "cool heat " .
Is it common practice/knowledge in the USA ?....it seems to be a well covered up down here .