Reasons for agricultural antibiotic use are twofold.

On the one had it is as you said, as a preventative measure to head off infection (which is obviously very bad), but it's worse than that - industrial farmers use antibiotics so they don't have to inspect and treat each animal. Just dump antibiotics into their food and if they are injured somewhere along the way it will hopefully heal on its own. Inspecting and treating each animal individually would be a lot more expensive.

The other reason antibiotics are given to livestock is to cause weight gain. If the antibiotics cost less than the value of the extra meat produced, then you make more money.

It's a fucked up practice that we'll be all pay for in a few decades.

Note the wiki page is an ok source, but is in need of some attention from someone outside the industry.

https://en.wikipedia.org/wiki/Antibiotic_use_in_livestock

Yes, and for increasing feed efficiency, they use low doses. Which is just perfect for selecting resistance.

At some point, it will become obvious enough that victims' estates will start winning lawsuits :)

How about a startup that uses image recognition from video feeds to identify and track individual anmials, and then tags those to be medicated once symptoms pop up? Or will the continuing dosage of antibiotics in the food prevent symptoms from appearing at all?

I see some great opportunities in technology for streamlining processes behind fair and high-quality agricultural products.

Even if they are sick, we shouldn't medicate them. Sick animals should be a loss ("too bad, you should've not let them get infected") because every other option creates resistant microbes that lead to human misery and death. Of course, even that wouldn't be a total loss; you can still turn the animals into pet food.

If we were serious about humanity's future, antibiotics would only be given in hospitals and all of your bodily waste would be incinerated until it no longer tests positive for antibiotics. You'd leave the hospital with a shaved head too, since hair may come to contain the antibiotics as it grows.

The real issue is that continuous low dosing of antibiotics increases weight gain, for not entirely known reasons, even when given to animals that don't otherwise appear sick.

This is a case where government just needs to step in and ban the practice.

This sounds like an "Internet of things" opportunity: an implant that monitors an animal's temperature, antibody levels etc. Then they could target only the animals with telltale symptoms.

The implants still have to be cheaper than the antibiotics.

The implants would likely be pretty cheap -- a one time purchase of an RFID sensor encased in glass or similar non-immunogenic coating. RFID tags are on the order of a few cents. Probably this type of sophisticated sensor is going to be more like a few dollars in quantity.

The reader and the software are going to be a few hundred dollars or maybe a couple thousand. But it's a one time investment, plus ongoing implants as the herd changes over time.

I suspect the main selling point is going to be the one-time capital investment aspects and the fact that antibiotics are being painted as an undesirable additive in meat and dairy. When the general public starts to dislike a substance, suppliers scramble to distinguish their products, e.g. "No added growth hormones" and the like.

So you're saying the correct answer is a massive tax on all antibiotics not dispensed in response to a human doctor's prescription for a patient that is seen?

How does that address the practice of using antibiotics because it makes more meat and is profitable?

It also doesn't address the fact that it's dirt cheap to buy these antibiotics in bulk, but what if we throw a startup at it??

Both those points are valid, however possibly there is a market for people who would pay more for meat that they know hasn't been pumped with antibiotics?

Maybe the startup could manage to do it for a cost that's less than organic meat?

Exactly.

Example: almost all turkey meat that's so in fashion today comes from farmers that use antibiotics as preventative measure. I personally source meat from small family run farms that adhere to biological agriculture principles, (there only ill animals get antibiotics and those aren't butchered and sold later as meat).