How can you tell they are Swiss, Jerome? Is it because they are neat and boring?
Cows are never boring.
European cows wear ear tags. This is supposed to allow traceability of the milk and meat products done to one individual cows, preventing -purely as a theoretical example- that one would get -say- horse meat in ground beef for lasagna, etc... But I digress.
The ear tags bear a country symbol (here CH, which stands for Switzerland - Confederatio Helvetica) and a set of numbers telling the farmer and the individual cow in the herd. The tags are machine-readable. Conspiracy theorists would probably believe that this is a plan from the NSA to control the world's meat production by photography. Conversely, posting a picture of a cow in the Internet is a bit like posting a picture of a model with her name and social security number...