I know the suspense has been killing you. The answer to the latest What in the the World is that Farm Thing? is: silo blower.
To me, the most fascinating thing about farm machinery is its relative simplicity--at the least the vintage of farm equipment we have around here. The blower works by using the tractor to operate a powerful fan that then blows the chopped up corn up, up, up into the silo.
The corn is then fed to the cows, who twice a day produce 100 pounds of manure a piece. They also give milk.