Have you ever wished to shove up your hand in the stomach of a cow? If yes, then Swiss Farmers are the ones who can offer you a chance to do that. If you see giant stomach holes in cows, remember that it is placed there for a reason and these holes are called rumen fistulas.
A hole is cut on the sides of the cows and then a tube is placed such that it goes down directly to the stomach.
The hole is always open because a rubber gasket is placed along on the opening and it is also sealed with a special cap.