The Irish Farmers' Association has expressed relief that a suspected foot-and-mouth case in Tyrone has proved negative.
Blood tests from the Pirbright laboratory in London show the Tyrone cattle are not suffering from the disease.
It means the North's hard-won regionalisation status has been saved and meat exports to the EU can be restarted.
The farm on which the animals were found is near the town of Cookstown, about 40 miles from the border with Co Monaghan.
The animals had been suffering symptoms similar to foot-and-mouth.
The North's Agriculture Minister, Brid Rodgers, has warned that vigilance cannot be dropped in the continuing battle against the spread of the disease.