The lucky beast escaped injury after her ordeal but the animal charity warned today that fly tipping can cause serious harm to animals.
Curious ... stuck cow
The RSPCA was called to rescue the heifer from a field at Higher Fraddon, St Columb, Cornwall.
It is one of the more unusual things we had had to rescue an animal from, said RSPCA spokeswoman Jo Barr today.
Young cows are quite curious, and she probably thought there was some food inside the drum, she added.
A member of the public spotted the frustrated animal trying to free herself from the metal drum.
RSPCA inspector David Hobbs was sent to rescue the heifer and she returned to her herd unharmed.
The cow will surely not make that moo-stake again!