Practically everything from NZ will be grass fed, so if in doubt you are usually safe buying products from there.. Anchor is the big brand, exported around the world, and confirm grass fed on
their website. Tastes delicious! I'm pretty sure Australian will be good too.
That's what I do when in doubt when Anchor is sold out - I just look for something from AU or NZ that hasn't been filled with water.
In fact all beef products from NZ are really good, due to apparently strict regulations on additives, hormones, etc