That is true. Question is why. In NZ our beef is still exclusively reared on pasture (with hay and winter crops like brassicas for winter feed), I've never understood why there's such a move to feeding grain to cattle overseas.
- Feed lots can fit a whole lot more cows per acre.
- Corn tends to fatten up cows more (and more quickly) than grazing.
- Increased fat content = meat that grades higher and tends to sell for more meaning you also earn more $/lb on top of the other reasons.
Basically, it was determined that corn was the cheapest way to generate certain caloric targets. This achieved that objective and also secondarily helped with certain political objectives. So there's a whole subsidy and trade system around corn growth that basically stifles everything else.
The outcome for agriculture has overall been devastation for all but the largest operators. The "scale up" makes it impossible for all but the largest farms to compete. When my parents were kids in the 60s, a diversified, smallish farm was a sustainable thing. When I was a kid in the 80s/90s, they concentrated on bigger dairy or corn operations. Today, they're going out of business or make money selling doughnuts.
Also feedlots.