A vet from the Department of Food and Rural Affairs has failed to persuade a smallholder to let a calf be killed, amid fears of bovine tuberculosis.
Fern is due to be shot by government officials
Sheilagh Kremers wants a second assessment of her calf Fern at her farm near Newton Abbot, Devon.
She said it was in protest at the government's policy on bovine TB, which can be spread to cattle from badgers.
Government policy is to shoot the animal before carrying out post-mortem tests to find out if it was infected.
The vet met Mrs Kremers on Tuesday and tried to persuade her to change her mind.
Ms Kremers' herd of 12 pedigree Dexter cattle was tested for TB two weeks ago. Fern was the only one that was found to be a TB "reactor".
This means the animal had come into contact with the disease, but vets will not be able to tell if it actually has bovine TB unless it is slaughtered and a post-mortem examination is carried out.
Ms Kremers, 63, told the BBC's Radio 4 programme Farming Today that she was taking a stand to save Fern and against the government's policy of killing cattle but not badgers, which also spread the disease.
She said: "I'm not going to allow them to take him away. I really want a retest.
"A stand has to be made. Too many of them [cows] are being put down."
The Department for Environment, Food and Rural Affairs (Defra) said it was concerned as farmers about the problems TB had caused and was currently consulting on whether there should be badger culling.
Both Ms Kremers and Anthony Gibson, South West Regional Director of the NFU, have asked for Defra to carry out a second test on Fern.
Defra said second tests were only given where there was a strong margin of doubt. It said the tests were more than 77% reliable.
The farm is under TB restrictions and the calf has been isolated.