EASTERN WISCONSIN — Rural Wisconsin is crossed with state highways, but you might not recognize them. Two-lane country roads dotted with red barns, granaries, and farmhouses, where passing is nearly always permitted if you feel the urge to tear around the loaded semis and tankers that rule these parts. Shiloh Dairy is nowhere near the freeway, but Route 10 will take you within a stone’s throw. Nestled into the rolling countryside of Wisconsin, 25 miles west of Lake Michigan and the same south of Green Bay, Gordon Speirs keeps more than 4,000 head of cattle here.