After Steve and Lori Dockendorf's two oldest children left their dairy farm to go to college, the husband-and-wife owners of a 100-cow farm in Watkins, Minn., had to figure out how to replace the labor they'd lost. The traditional solution would have been to hire a couple of extra hands. Instead, the Dockendorfs went with robots: robots to help feed the cows, robots to help clean the barn, even robots that can milk the cows.