Basically none. We will continue to dose cattle with antibiotics as long as there is additional gain from doing so, regardless of how profitable cattle without antibiotics are.

Or until legislation forces big AG to stop doing it for the sake of everyone else.

So you're saying if farming antibiotic free cattle is twice as profitable as today, and farming antibiotic cattle is loss making, farmers are still going to farm antibiotic cattle? You know farms are businesses, they are motivated by money.

No, what they are saying is that cows fed with seaweed AND antibiotics are still more profitable than cows fed only with seaweed.

Antibiotics in farming is used in order to keep animals in a environment where if it wasn't for the antibiotics they would get sick.

Factory farms, or concentrated animal feeding operation as it are sometimes called, are crowded and stressful for the animal. Hygiene, temperature and ventilation are often bad. In combination this create a environment where sickness is rampant and currently antibiotics is the primary tool to keeps it functioning enough to be profitable. Seaweed is extremely unlikely to replace antibiotics in those kind of operations.

> Antibiotics in farming is used in order to keep animals in a environment where if it wasn't for the antibiotics they would get sick.

I'm not sure that is entirely accurate. Prophylactic treatment to avoid diseases is one reason for antibiotic usage, but more growth promotion is a much bigger factor.

The main reason that cattle are fed antibiotics is that a low dose of antibiotics makes them grow faster.

This use has been outlawed in the EU, but according to [1] antibiotic use for other reasons has increased since then, so it sounds like farmers only claim to use antibiotics against diseases, when they are actually only interested in the growth advantages.

[1]: https://fstjournal.org/features/antibiotics-farming

Beef cattle only spend the last few weeks of their lives on feedlots. Otherwise, they are grazing. You should visit a working ranch/farm sometime.

I thought it was also because corn-based diets increases likelihood of stomach ulcers in cows. The antibiotics fight the h.pylori bacteria which causes the ulcers.