I don't disagree with the general premise that reducing antibiotic use in livestock would be helpful in reducing the emergence of resistant strains of bacteria. I have to take issue, though, with the assertion that even eliminating entirely their use in the food industry would provide any sort of enduring solution. It would not.
The dirty little secret about antibiotic resistance that no one wants to talk about is this: resistance emerges from repeated use of different antibiotics in the same human, many of whom are not supposed to (according to nature) survive anyway. This group includes critically ill or injured people, cancer patients, patients with chronic organ failure, and most importantly old people. All of these groups have the common characteristic of impairment of immune function.
Antibiotics don't really "cure" infection. They kill enough of the circulating organisms so that the host immune system can take care of the rest. Some very good antibiotics don't kill any bacteria, they just stop replication. So if you actually wanted to create a petri dish for resistant organisms, you would take a host with poor immune system function, infect it, and give antibiotics that kill most of the bacteria and let the rest play on.
In this regard, the best possible "petri dish" is the transplant recipient. In something of a bittersweet triumph for modern medicine, the exact mechanism by which VRSA (vancomycin-resistant Staph aureus) would later emerge was predicted, carried out in the lab in an elegant esperiment which demonstrated the mechanism (plasmid exchange of the VanA resistance gene from VRE into Staph), and later confirmed when the first case emerged, in the Transplant ICU of the University of Pittsburgh Medical Center (ironically where transplants were originally perfected).
Biological systems have tons of complexity so there will be new drug targets in the future, but the obvious ones have been hit by now, so new drugs will be more expensive. The balanced approach would be to reduce antibiotic use on the human end, which inevitably brings up discussion of limits of care and "death panels." It is no accident that these pathogens tend to emerge in the U.S., where such discussion is difficult with our demographics, and where the entire population (doctors included) holds an almost mythical belief in the power of antibiotics. All they do (seriously) is rearrange the population of bacteria that inhabit your body. Sometimes that helps, a lot. We need to be honest about when those times really occur.
tl;dr Stop all the use of these drugs in livestock and you will only change the rate of emergence of resistance, not the fact. This problem is not going to go away.