The manacled cow

One curiosity from our Wrenbury trip that I omitted to relate first time round. I know that Conan Doyle didn’t write a book called Sherlock Holmes and the Case of the Manacled Cow but he damn well should have. Then I might know why we espied two cows en route clad in very fetching leg irons. We collectively wondered why they might be wearing them and came up with the following:

a) They are escape artists and possibly convicts
b) They are buckers. With a B.
c) They like to run fast which causes the milk to turn to cheese, which causes all sorts of problems when it comes to teat-touching time.

Now this would be like Call My Bluff if I knew one of the above was correct but I don’t. So could anyone enlighten me? Is there an udder explanation?