Well to start we have a 20% head start just with the dollar. Then I think you'll find our land prices cheaper. Those two things alone make a huge difference. That's also why Canadian feedlots have been attractive destinations for American cattle.
I don't know if I would want to get into a debate over how many cows we can run per acre with you.... I expect that changes pretty dramaticly within both countries.
I'm not saying it's cheap to raise cattle here either, but where can you buy a 1/4 for $40,000 USD down there?