I prefer the term "No Fed Antibiotics".  What I question is what is different between a hamburger from a cow who never received a treatment and a cow who had the misfortune of stepping on a nail and the farmer wanted to give a shot of antibiotics to be safe?  I have considered the idea of having two labels.  One for animals who have received a treatment, one for animals who have not.  After getting input from consumers in response to how I rarely use them, and I how I would use them and what for, they don't really care.