No they're not, at least they're not pasture. They're either already farmed fields or they're wild meadows. Putting meadows to intense use would destroy whole ecosystems that may look like "just grass" from afar, and farmed fields are obviously already in use.

> No they're not, at least they're not pasture.

Thanks for telling me what the fields around me are!

I don't think anyone in this whole thread was talking about your local fields here.

There's not enough grass-land in the world for everyone to eat grass-fed beef. That's the whole point of not feeding them grass in the first place.