Cows in Fukushima radiation zone graze with new purpose

In an abandoned Japanese village, cows grazing in lush green plains begin to gather when they hear the familiar rumble of the ranch owner's mini-pickup. This isn't feeding time, though.

Instead, the animals are about to be measured for how they're affected by living in radiation - radioactivity that is 15 times the safe benchmark. For these cows' pasture sits near Fukushima, a name now synonymous with nuclear disaster.

The area was once a haven for agriculture with more than 3,500 cattle and other livestock. Ranchers who refused a government order to kill their cows continue to feed and tend about 200 of them. The herds won't be used as food; now science is their mission.