Misdiagnosis of bluetongue and delays in appropriate treatment can prove fatal for animals struck by the disease, with mortality rates peaking at over 60%, says NFU livestock adviser Alastair Johnston.
Secondary problems such as abortions and premature calves, combined with up to 100% infertility in breeding males, has also caused severe problems in French livestock production this year.
"After the initial outbreaks in 2006, there was an air of complacency within France," Mr Johnston told Farmers Weekly after an NFU-organised tour to north-east France. "They thought they had dealt with the virus successfully. But now they have over 7500 cases throughout the country and the additional problems which accompany the virus are causing great concern."
Working alongside their French counterparts, the FDSEA, a 15-strong party of NFU staff and livestock farmers were taken to a number of sheep, beef and dairy farms in the Valenciennes region.
The initial briefing at the regional FDSEA described how bluetongue was present on every holding in the region, with anything between 5% and 62% of animals showing some clinical signs. And of those infected, 15-63% died in the early stages.
"It was clear that, although there might be a high midge population on a farm, it does not necessarily mean that all animals will be infected," said Mr Johnston. "The important issues are the level of infection in that midge population and its ability to feed and breed."
The amount of livestock, the local habitat and farm layout all contribute to the degree of infection. Densely wooded areas with wet or waterlogged ground are ideal sites for midges, as are manure heaps. And the closer these are to the animals, the quicker the disease can spread.
"The first farmer we visited was well into lambing his 350 ewes and, despite the large pen of orphaned lambs due to higher-than-average ewe mortality, he remained upbeat," said Mr Johnston.
This was thanks in some part to a supportive French government, which encourages farmers to report all cases by paying compensation of €43 (£30.50) for sheep of any age that have died of bluetongue. Fallen stock collection charges have also been waived for animals of over 40kg.
But the main reason for the optimistic attitude was the farmgate price for French lamb of about £80 a head. Lower input costs due to collaborative buying also helped the farmer remain profitable and so pay for medical treatment for infected animals.
- Sourcing fertile males has been a serious problem for French sheep farmers this breeding season. Many males are proving to be infertile due the higher-than-normal body temperature caused by being bluetongue positive.