'Biggest threat' to livestock since Foot and Mouth

It is considered the biggest threat to livestock since the Foot and Mouth outbreak a decade ago. The Schmallenberg virus causes birth defects in sheep, goats and cattle and there is still no vaccine to combat the outbreak.

Scores of farms have already been affected. Now, the government department DEFRA has taken the unusual step of issuing a warning about the disease, with the lambing season underway already. David Hirst reports.