Devon's farms have more cases of the deadly Schmallenberg virus than any other county - 130 overall.
The disease causes stillbirths and birth defects in sheep and cattle and is carried through insects. There have also been nearly 70 cases in Cornwall.
The National Farmers Union says it's vital that a vaccine is made available this year.
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Bob has the forecast from Devon, Cornwall, Somerset and Dorset.
Bob has the forecast for Bristol, Somerset, Wiltshire, Gloucestershire and Dorset.
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