Food labels have always been confusing and none more than those on chicken. Lately there has been advertising from a well known poultry company which states that by Federal Law all chicken has to be free of antibiotics, suggesting that chicken "raised without antibiotics" is not a necessary label.
Here's where it is confusing. If a label says "no antibiotics ever" it means that antibiotics have never been administered. The Federal Law they are referring to in the commercial states that there is to be a withdrawal period from when the antibiotics are administered until the bird is slaughtered. This is supposed to allow time for the antibiotics residue to dissipate. The wording in the commercial is "By Federal Law all chickens must be clear of antibiotics before they leave the farm."
Antibiotics for some reason make the chickens increase in size at a rapid rate which is one of the reasons poultry farms like to use it, but the concern is that overuse increases Superbugs resistant to antibiotics.
I'm sticking to the chicken that has nothing added "ever" including deli meat which sometimes has nitrates and caramel coloring added, but that's a whole other story.
You can read more about terms here