I'm going to say something very controversial 😆 Grass fed beef is a scam. All beef is grass fed, the best is grain finished. It would cost a fortune to raise cattle on all grains. No ranch could afford to do that. Grain finished beef has the nice marbling and all that yummy, necessary fat. Quality of the grass & the grain is what matters. "Grass fed" just mean lower feed bills, smaller, less nutritious steaks, and higher prices because those cattle yield less weight.
Discussion
Nah in USA they actually have feedlots that do from weaning age all the way to slaughter, the cattle are never allowed outside, never allowed to eat grass, never allowed to see sunlight.
It's incredibly cruel.
Outside of USA and Canada it's practically unheard of though.