A 14-year-old girl was horrified to find the severed head of her pet cow in a farm field and the rest of the carcass missing.

The severed head of pet heifer Duchess in a field at Thamesdown Farm, Elsfield

John Goodey, who owns Thamesdown Farm, in Elsfield, near Oxford, said his teenage niece was traumatised after realising that her pet Duchess, who was being groomed for competition at agricultural shows, had been slaughtered by trespassers.

The beheading comes after 55 lambs were shot in three separate incidents at a farm in Horton-cum-Studley this month.

Mr Goodey, whose family runs Thamesdown Farm Nursery, in Garsington, said: "We're all absolutely devastated. She has looked after her since she was six months old. She was getting her ready for the Thame and Royal shows. She handled her from when she was a baby.

"She's very traumatised. She doesn't want to go back into the field and she won't eat meat. We're all worried they will come back for the other heifer, Lollipop.

"What would have happened if she had gone to the field when they were slaughtering Duchess? It just doesn't bear thinking about what they would have done to her.

"The heifer was tame and associated with humans more than most cows. It's just an awful death for her to have when she trusts human beings.

"Although she's a farm animal, she was a pet and was part of the family." He added: "It's like we're living in the Middle Ages -- it's barbarous. The fact that somebody can come in and butcher an animal to death, hack a beast to pieces and get away with it scot-free, it's terrible."

Ian Marriott, of Oxfordshire County Council's trading standards department, said: "It's not uncommon. There have been incidents along the M40 corridor and we suspect it could be going to London.

"There will be people around with the expertise to butcher it. It could reappear in the food chain anywhere.

"The spinal cord should be take out and disposed of properly or there's a risk of BSE and the meat could have been contaminated when the head was severed."

He added: "For something like this, they have to be fairly organised. It's unusual for an animal to be killed on site.

"If anyone is offered meat on the cheap or in unusual circumstances, then think very carefully -- it might be contaminated."

Andrew Duffy, of Oxford, Thame and Henley National Farmers' Union, said: "It's either going in someone's freezer or in a restaurant. It will be used by the people that killed it, or sold off.

"It could go into a butcher's or a shop. I suspect it's more for domestic use.

"Last year, two cows disappeared and sheep have been known to go missing or be shot with crossbows in the past."

Sophie Wilkinson, of the RSPCA, said: "We condemn any animal cruelty and anyone who killed the cow in such a way wouldn't have had the skills to do that. It would have suffered before it died."

Anyone with information about the incident should call Pc Mark Lacey at Cowley police station on 08458 505505, or Crimestoppers anonymously on 0800 555111.