Farmers who are calving cows during the upcoming spring have been urged to be vigilant for signs of malformed calves due to Schmallenberg.

It comes as early lambing sheep flocks across NI experienced a sharp rise in abortions and malformations due to the virus.

Newtownards-based vet Cormac White said cows that are at highest risk of Schmallenberg are due to calve down throughout the spring period.

This is because the key stage of pregnancy for picking up the virus from infected midges is two to six months in-calf and midge activity peaks in the late summer and early autumn.

“Anyone calving cows from March through to May needs to be mindful of the possibility of Schmallenberg. By June, you would hopefully be out of the window.

“If there is a difficult calving this spring, you need to go slowly and thoughtfully in case it’s a malformed calf. Don’t just start pulling hard with the calving jack,” White said.

There is currently no vaccine available for Schmallenberg and there is no treatment to prevent malformations or abortions once animals are infected during the susceptible pregnancy period.

For sheep, the key period for pregnant ewes to become infected with Schmallenberg is between 25 to 50 days in-lamb.

At present, lambing in pedigree flocks across NI is generally finished and most commercial flocks have not started yet.

White is hopeful that the worst of malformed lambs due to Schmallenberg is over, although a risk remains as the mild autumn meant midges persisted later than usual in some places.

“For ewes lambing now, the end of the risk period for picking up the virus is late October, so midge activity was starting to die down around then.

“Barren rates could be an issue going forward. Ewes that are tupped in October or November and get infected before 25 days in-lamb might abort early on or not hold at all,” he said.