As sheep farmers are well aware, the weather in early spring can fluctuate from extreme cold to warm sunshine within a few days.

A cold snap followed by rapid warming can result in a sudden and significant challenge to young lambs, as nematodirus larvae hatch in large numbers.

The delivery of an important free-of-charge service from SCOPS this spring to help sheep farmers monitor the risk to their lambs is very timely, as the first areas in the UK have registered as ‘moderate risk’ in the last few days.

The SCOPS Nematodirus Forecast is now live – a web-based facility allowing sheep farmers and advisors to check the nematodirus threat this spring and summer as new season lambs start to graze more grass.

The interactive forecast map is updated daily using data from 140 weather stations around the UK. Users can zoom into their area, select the nearest or most representative weather station and act according to the predicted risk (presented in a ‘traffic light’ format) to their particular farm.

The forecast provides general advice for sheep farmers, advisors and vets to use in partnership to decide the most appropriate approach for individual farms.

‘Nematodirosis is a particularly nasty disease’

Speaking on behalf of SCOPS, Lesley Stubbings said: “Nematodirosis is a particularly nasty disease in lambs, causing a high number of mortalities and stunting the growth of many others.

It is caused by the Nematodirus battus worm which, under certain climatic conditions can strike very quickly, with little or no warning.

“Cold weather delays worm hatching so, when we get a sudden change in temperature, as is so common in spring, it can trigger a mass hatch.”

Dr. Hannah Vineer of Liverpool University developed the forecast for SCOPS.

She said: “When the predicted risk increases in the local area, farmers should think about ways they can avoid or prevent infection to protect their lambs, for example by moving them to fields not grazed by lambs last year.

Farmers should also be mindful that risk will vary from field to field.

“The Nematodirus Forecast provides useful guidance to help farmers assess the risk of each group of lambs based on the history of the field, as well as instructions to adjust the risk level for your farm based on aspect and altitude,” she concluded.