Yeah but who owned the ground in the are first? The farmer has a right to expand his operation. That said, I'm against confined feeding operations for a variety of reasons. But we recently had a local case where a farmer simply built a barn that was maybe 20-25 percent larger than the old barn which had burnt in a lightning strike. He added some 20 cows, not a confined feeding operation, just a dairy operation, got sued by a nieghborhood association about 2 miles away claiming a property value drop because of the smell from the additional cows... He won as there was nothing wrong with what he did but it cost him several hundred thousand dollars and about 5 years of fighting.
Sorry, but if you move out near farms, you have no choice or say in what that existing farmer does with his/her operation.