OT and Andy, I can't understand why you are having problems with the Z-tags. They are far and away the best we have used. Are you putting them in holes made by prior tags, such as cows? That probably could be part of the problem.
Are you using them in calves ears? My husband really likes the fact that he doesn't have to pack the buttons around either. Gosh, everyone in this area is sold on the Z-tags.
I really am puzzled by your comment. We did get a bag that the end on a few fell off behind the ear, and the tags fell out, but that was a bad batch. Heck, maybe you got into that same batch. We have used them for years with no problem at all. But we did have a little of that this year. You can see that the end isn't quite right before you apply the tag. If you have any left, take a look at the end on the back of the tag.
Let me know what you find, I am curious.