A drop in demand for the ponies from riders and meat traders has seen prices fall from �40 several years ago to as low as �2.

Local farmers say the industry is in crisis and many are considering slaughtering their herds, prompting fears that the animals could disappear altogether from the Devon moor.

One farmer, Neil Cole, said: "People with a lot of ponies are just shooting them or giving them the big hit. There's literally nothing else we can do with the Dartmoor ponies.

"There's only a certain limit to the amount we can sell to people for riding ponies, the rest we have to have a meat trade for and if there's no meat trade I'm afraid there'll be no Dartmoor ponies on Dartmoor any more."

The Dartmoor Park Authority is looking at other ways of keeping its unofficial emblem on the moors and animal welfare groups are also trying to find a solution.

Jeff Harrington, from the League for the Protection of Horses, is "concerned"

Jeff Harrington, from the League for the Protection of Horses, said: "It's an unfortunate fact of life that the farmers are producing something that the riding public or the general public can't buy and don't want to buy and they're going to be recycled into the meat industry.

"As a welfare organisation we are obviously concerned with that."

Sylvia Phillips, of the Devon Horse and Pony Sanctuary on Dartmoor, said farmers had to cut down the numbers of ponies by removing the stallions.

"It is up the to farmers to manage the ponies," she said.

Little joy at auction

At the first auction of the season for Dartmoor ponies, in Tavistock, Devon, prices were better than expected as many were bought by concerned members of the public.

About 450 ponies were sold at auction, but prices were low

Ralph Calvert said the five animals he bought for just �52 would now roam free on his land at Mithian in Cornwall.

Mr Calvert said he came to the sale intending to buy two or three animals "after hearing the sad story of what they were used for".

He said: "I will keep a diary of their progress, and they will be there for people to see and touch."

Three more ponies were saved from slaughter by husband and wife Janet and John Holden, who bought three animals for �43.

They will graze the animals on their seven-acre Willow Valley Camp site.