The incidence of bovine TB is said to be rising

The sweeping response is the first time in seven years that a whole herd in Scotland has been taken out because of the disease.

Vets ordered the slaughter at the un-named farm near the village of Dolphinton, South Lanarkshire, after more than 60 of a 300-strong herd reacted positive for TB.

The president of the Scottish National Farmers' Union, John Kinnaird, said: "TB is such a virulent disease that it'simportant it is taken out very quickly and we have to ensure that it doesn't become endemic and this is unfortunately the only way to deal with it."

The last whole-herd slaughter in Scotland was in Arran in 1996 but there have been many less severe outbreaks since then and they are on the increase.

Most of the 29 Scottish cases last year were in Dumfries and Galloway and the Borders.

TB 'hotspots'

Part of the reason is that some farmers restocked after the previous year's foot-and-mouth epidemic with cattle bought from TB hotspots in the south of England.

Cases are mostly dealt with by killing only the infected animals and monotoring the rest.

But vets have warned of the potential for an epidemic unless farmers exercise the utmost caution when buying animals from high-risk areas.

They fear it could run out of control if bovineTB gets into and is spread through wild populations of badger and deer.

Some farmers have blamed badgers for spreading TB among their cattle and have demanded culls to curb the risk.