I am assuming he/you are referring to the lines/striations in the breast feathers. Not sure why your gobbler has them, but they are probably just the result of some genetic anomaly in your bird. It might be a rare occurrence in that gene pool...or could be a bit more common in other birds from that particular location.
...Also, not sure why your taxidermist would refer to that appearance in the feathers as being "clipped" or "barbed"...might be a colloquial term thought up by someone who has seen that anomaly before from that region, and often enough that it warranted being called "something". I've personally never heard those terms before, and am not sure how they would apply to that particular appearance feature.
