I was surprised to learn recently that we import a LOT of cattle. It's the reason many other countries will not take US beef, because the provenance of our beef isn't as precise as it needs to be, for those foreign consumer laws.
This is true of a lot of our food. Trump, now and in 2016, has been trying to force the UK to buy US chicken and the Brits are NOT having it because US food standards are below that of the UK.
We also treat our cows with antibiotics that a lot of countries ban. A lot of our meat is also treated with chemicals that other countries ban.
It's why Europe won't import a lot of US beef.