Spring lambing in the U.K., Europe’s biggest sheep-meat producer, has taken a deadly turn as a livestock virus, which causes stillbirths and deformed lambs that die soon after birth, spread to the country’s flocks.
The Schmallenberg virus, named after the German city near where it was first identified in November, has been found in seven European Union countries. It was probably spread by biting midges last year, infecting pregnant sheep, cows and goats, according to Germany’s Federal Research Institute for Animal Health, which discovered it.
The impact of the disease on livestock births is becoming clear now because sheep gestate for five months and cattle for nine months, said Toby Kemble, a veterinarian at Wensum Valley Veterinary Surgeons in Fakenham, England who saw cases of Schmallenberg virus on farms in his practice this month.
“It could be the tip of the iceberg,” Kemble said by phone yesterday. “We don’t know when the peak is going to be.”
The U.K. is the world’s fifth-biggest producer of sheep meat after China, Australia, New Zealand and Iran, according to data from the United Nations’ Food and Agriculture Organization. The country had 14.9 million breeding ewes as of June 2011 with 16.5 million lambs under one year, government data show.
Of the 10 sheep farms in Kemble’s practice where lambing has started, eight had cases of Schmallenberg virus, with average infection rates of about 5 percent and one instance where 25 percent of lambs were born dead or deformed.
The virus has been identified in samples from 58 farms in England, including 55 on sheep farms and three in cattle, the U.K. Animal Health and Veterinary Laboratories Agency reported two days ago. The virus may have been spread by midges blown over the English Channel, according to the agency.
The virus is unlikely to cause disease in humans, though it cannot be excluded, the European Centre for Disease Prevention and Control wrote in a Dec. 22 report.
France confirmed 29 cases of the disease to the World Organisation for Animal Health on Jan. 31. There are now at least 200 to 250 infected sheep farms in the country, as well as about 40 cases of cows with the virus, according to Serge Preveraud, president of France’s sheep-growers lobby Federation Nationale Ovine.
“This number is rising every day,” Preveraud said by phone from Paris yesterday. “Obviously the livestock breeders are worried. When there’s an epidemic and you don’t know when it’s going to stop, you’re worried.”
Infection rates on French farms with the virus vary from 5 percent to 30 percent, according to the FNO president. Complications during lambing due to deformed young are also causing some ewes to die, Preveraud said.
French sheep farmers are missing out on about 100 euros ($132) per dead lamb, according to Preveraud. In England, where lambs are typically sold at heavier weights, the selling price is about 100 pounds ($158) per lamb, according to Kemble.
“It’s still an appreciable amount,” Kemble said. “You’ll have fed a ewe for 12 months to raise those lambs and then you’re not going to get any money back.”
The U.K. produced 289,300 metric tons of lamb meat last year, up from 277,400 tons in 2010, according to data from the Department for Environment, Food and Rural Affairs. Lamb retail prices have climbed 16 percent in the past year, according to inflation data from the U.K.’s Office for National Statistics.
In Germany, 601 sheep farms, 36 cattle holdings and 31 goat farms have tested positive for the virus, according to the animal-health institute, known as the Friedrich-Loeffler- Institut. The Netherlands, which first found it in December, on Feb. 9 reported confirmed cases at 88 sheep farms, five goat farms and three cattle farms.
Germany and the Netherlands
Friedrich-Loeffler-Institut scientists discovered the virus in the blood of cattle in Germany and the Netherlands that suffered from fever, reduced milk production and diarrhea in the summer of 2011.
The scientists who isolated the virus in November have provided it to vaccine makers, Franz Conraths, head of epidemiology at the institute, wrote in an online discussion organized by Farmers Guardian on Feb. 10. Any prototype vaccine will take “several months,” followed by safety and efficacy testing, according to the institute.
Experimental infection of cattle showed animals “rapidly” produced antibodies to neutralize the virus, meaning livestock may become immune after exposure, according to Conraths.
Italy was the most recent EU country to report an outbreak of Schmallenberg virus on Feb. 20, with cases in five goats and one in a cow.
“If we’re going to see more problems now it could be in the cattle,” said Kemble. “With regards to cattle, we’re only going to see a peak three or four months after the sheep peak. We’ve not had many cows that have calved, because there hasn’t been enough time.”LinkedInGoogle +1Print