From what I understand, they feed them grains if it's not grass-fed. They weren't grazing.
Discussion
Here, grass fed only means it’s been fed grass. All beef eats grass but some are brought into feed lots to be finished with “feed”. This still called and packaged as “grass fed”. If want to buy beef that has only eaten grass, you have to buy “grass finished” beef. Is it the same elsewhere?
Yes, grass fed doesn't indicate it's grass finished.
But grass fed is not the norm here. Anything that doesn't say grass fed is grain fed. That's my understanding.