Central Europeans eat a lot of meat and somehow they manage to keep prices under control without slamming animals with antibiotics prophylactically. Land and regulatory compliance costs are much higher than in the US too.
US farms are also subsidised. Maybe to a lesser extent than the EU but it's significant.
There are plenty of farms in the EU that house animals permanantly. I can't speak as to the differences in conditions between US and EU regulations regarding animal housing.
It's not at all clear that banning indiscriminate antibiotic use in the US would render farms financially unviable. There are significant trade barriers that mean that meat producers are somewhat insulated from world competition.
There would probably be a rise in the price of meat, but how significant is hard to say - there may be some research done on this, maybe not. I don't believe that meat in the EU is significantly more expensive than in the US