Logistics and relatedly prices I believe is why. The tradition there was because grass was cheaper to grow than hay to feed them. Now it is the opposite and has

Logistics and relatedly prices I believe is why. The tradition there was because grass was cheaper to grow than hay to feed them. Now it is the opposite and has probably been so for a while. Grass takes more time to fatten them for slaughter and it being cheaper to bring the feed to them than to cattle drive them around to even cheap feeds. Maize (the winner of the local grain corn title) is a type of grass technically but one whose mutated seed size and height are way up there and given that it is human edible (even the field corn variants which are terrible tasting) the trophic layer issues become egregiously obvious.