https://lemmy.zip/pictrs/image/5c433cba-a635-48ab-b875-3b5530480e89.webp

this seems to say (near the bottom there) that basically everything a cow eats (52 of 54 units or there about) is either grazed grass or crop residues, with only like 2 or 3 of those units (so about 4-6%, in round numbers) comes from crops grown to feed them. i don't really know the dietary composition of a chicken or swine, but, cattle, at least, get essentially no direct crops at all.