John, do you have a large feedlot? How many of them do not use implants or feeds with antibiotics? It's my understanding that you use them to compete. Smaller scale producers can find markets for "naturally produced" beef, not to say that some feedlots can't (such as Pineland Farms Natural Meats aka Wolfes Neck right here in Maine).
It's a touchy issue, I had it drilled into my head in college how to manage with rBST, being a dairy major and all. I was against the labeling of No Artificial Growth Hormones, unless there was a disclaimer that there is no significant difference. I have started to go the path of providing what the consumer wants. I promote that I don't use growth hormones or fed-antibiotics. Because I deal directly with the consumer I can tell them how when I use an antibiotic I follow the label, provide proper dosage, follow witholding time and track it in my database (cattlemax). As far as hormones go, I tell them the industry standard is the slow releasing implant behind the ear, and I don't use it. I will admit to them that I use hormones for breeding synchronization. When you have the chance to describe that to customers, they are OK with it, they can relate to what they would do for their or their families own health. What people seem to be most concerned with is the constant or sub therapeutic uses of hormones and antibiotics.