Farmers say they are "very concerned" about a new animal illness which can cause birth defects in livestock.
The Schmallenberg virus (SBV), which emerged in the Netherlands and Germany last year, was confirmed in the UK for the first time on Monday.
Cattle farmer Roger Long said: "We know so little about it. But of course we are concerned and the last thing we need is another virus to come over here."
Mr Long said his farm at East Dereham in Norfolk was "not a million miles away" from one of two sheep farms in the county where the disease has been detected.
SBV has been confirmed at two other sheep farms in England, one in Suffolk and one in East Sussex. The NFU said all the lambs which tested positive for SBV were stillborn or died shortly after birth.
http://www.bbc.co.uk/news/uk-england-16704067