New concerns over the spread of BSE have been raised after a cow born since the introduction of controls to eradicate BSE was confirmed to be suffering from the disease.

The cow, from the Dorset area was born on 25 August 1996, which is significant because it was after 1 August 1996, when extra control measures on animal feed containing mammalian meat and bone meal were implemented. There was some evidence that the cow had caught the disease from its mother, a method of transmission not previously proved, but that did not rule out a rogue batch of contaminated feed as a possible route. The government has ordered a special investigation into how the cow caught the disease and have insisted there was no risk to food safety.

But food safety experts said the case raised new concerns about the spread of the disease and called for a ‘transparent’ investigation.

Experts had predicted 19 cases of BSE in cattle born after August 1 1996 before the end of the year, yet this was the only one so far.

Because the animal was 44 months when it died, there was no possibility that it could have entered the food chain as anti-BSE regulations forbid the use of animals aged over 30 months in food production.

There is going to be a thorough and transparent investigation as to how the cow became infected and any implications for public health. This again reinforces the fact that many uncertainties still remain regarding BSE. They need to ensure that vigorous and effective controls are in place.’

Officials said the mother of the cow had not been identified as a suspected BSE victim.