Corn, people... American cows prominently eat corn.

It is extremely fertilizer and pesticide intensive, and entirely engineered. As pointed out elsewhere in this thread, the fertilizers are also fossil fuel based.

Yeah, this is a bit what I was getting at. But all I know about cattle comes from my family's cattle background in Eastern Montana and the high valleys of the SouthWest corner of the state. In both those regions, many cows are raised in naturally occurring pastures, eating native grasses, save oats which are sown as a cover crop.

However, my impression this is very unique and produces much less pounds of beef per acre than most places. The cattle breeds there are leaner and half wild. I'm hesitant to speak more definitively because I don't know specific statistics on how ranches in other regions differ. My impression is that the difference are substantial.

> ...fertilizers are also fossil fuel based.

True, but these only account for 1% of energy demand[1]. Fertilizer is all about the nitrogen, not the carbon. The carbon for the corn is taken from the atmosphere.

[1] https://www.sciencedirect.com/science/article/abs/pii/S09213...

What I should say is, not all American beef is fed from naturally occurring pasture land. In fact, a good deal of it is not.

At this point, nearly all agricultural land was converted a century ago. The trend now is more towards decreasing total agricultural acreage if anything?

No one in America has slash and burned a forest to feed cattle for a very long time.