MORE terrible news for our farmers. BSE may be able to jump species more easily than previously thought, scientists have reported. Not only cattle, but sheep, pigs and poultry could harbour the disease while showing no outward symptoms.

This suggests that mad cow disease is capable of spreading throughout our livestock.

Put like that, it is a devastating discovery. The implication is that no meat is safe from infection. But it is essential that the latest bulletin from the laboratories is kept in perspective.

We already knew that victims of CJD, the human form of BSE, harboured the disease for some time while appearing to be perfectly healthy. So the fact that other creatures can carry the potentially lethal abnormal prions without showing any symptoms should not come as an entire surprise.

The finding that the BSE prion can pass, unexpectedly, from one species to another is more disturbing. Again, it is crucial that this is kept in context. There is a significant leap between experiments with laboratory mice and the real world.

It was right that the scientists published their results. The initial BSE crisis was worsened by ham-fisted attempts to keep the public in the dark.

Nevertheless, the report is a hefty blow to Britain's crisis-torn agriculture industry. Farmers who survived the BSE crisis were hauling themselves to their feet again, but they will be sent reeling by this despatch.

To reduce the damage, ministers must approach the matter with extreme caution. They do not want to give our trading partners another excuse to refuse British meat.

The new threat appears to be tiny. This is not a time to impose further bans, but to check that current health safeguards are still appropriate.

Understandably those who have lost loved ones to nvCJD are calling for action. But the predicted epidemic has yet to manifest itself. We should not lay the remainder of Britain's farming sector to waste over what is, at present, nothing more than a theoretical risk.