The cattle arrive in perforated silver trailers called cattle pots that let in wind and weather and vent out their hot breath and flatus. It’s hard to see inside a cattle pot. The drivers are in a hurry to unload and leave, and are always speeding by. (When I ask Lefty how meat gets bruised, he says, “You ever see how those guys drive?”) The trucks have come from feedlots, some nearby, some in western Nebraska, a few in Iowa. The plant slaughters about 5,100 cattle each day, and a standard double-decker cattle pot holds only about forty, so…