> Realistically, I think most US cattle is fed from domestic feed

I believe you could make this "all" without loss of accuracy, at least to three significant figures. Might have to relax "domestic" to cover Canada and Mexico, neither of which is deforesting to produce fodder.

The US is a major exporter of the crops fed to cattle, and livestock in general. The lack of supply chain transparency your counter-analogy relies on is nowhere in evidence in US agriculture.