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 have had to rescue an animal from," Jo Barr of the RSPCA said.

"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 animal trying to free herself from the metal drum.

RSPCA inspector David Hobbs, rescued the heifer earlier this month and she returned to her herd unharmed.

He said: "Most people hate to see fly-tipping as it is an ugly blight on the landscape, but incidents like these highlight that as well as the visual impact the rubbish can also endanger animals.

"The heifer was probably curious to see a new item dumped in the field and curiosity would have turned to panic once she got her head stuck in the drum and was unable to get it out.

"If people disposed of their rubbish properly many animals would be saved from injury and death.

"A large proportion of the injuries the Society's inspectors, animal collection officers, vets and wildlife hospitals deal with are caused by carelessly discarded rubbish and fishing litter."