vacuum-packed cows 

A vacuum-packed cow can be found in most fields in Britain throughout autumn and winter. Many believe that the large cylinder black bags are full of hay, but that is an urban legend. Inside these mysterious bags are on average three vacuum-packed cows. These cows have been dehydrated and vacuum packed in order to keep them safe until spring. If you had ever wondered why there were a lot less cows in the fields in winter, you now know. Obviously not all cows are vacuum-packed, as it is still a new technology, and can be dangerous to cows, or require them to have months of therapy afterwards.

Farmer Brown started vacuum-packing his cows around October, so they could get used to their vacuumed environment.

vacuum-packed cows by Stephen W. Thomas May 9, 2005