The bout of warm weather forecast this week means sheep farmers should be on their guard against nematodirus, warns the Sustainable Control of Parasites in Sheep (SCOPS) group.
Most lower lying areas of England, particularly South and East England, are at moderate risk which means they are within 10 days of hatch according to the online SCOPS nematodirus forecast map at www.scops.org.uk/nematodirus.
The map is updated daily using data from 140 weather stations. It tracks changes in nematodirus risk through spring and early summer. Farmers and advisers can select a point on the map nearest to them before viewing advice on how to relate the predicted risk to a particular farm.
Treatment options and possible management actions are also provided, which SCOPS advises sheep farmers should use in consultation with their vet or adviser to consider the local risk and when/if to treat lambs.
Lesley Stubbings of SCOPS said: “The rapid change from the relatively cold weather in March and early April to the forecast for the second half of April means a mass hatch of over-wintered nematodirus larvae is highly likely in some areas.
“This poses a serious danger to February and March-born lambs grazing fields that carried lambs last spring.”
Dr Hannah Vineer, involved in developing the online forecast, said: “Farmers need take variation into account before acting, which could be from farm to farm and even field to field. Aspect and altitude, as well as a fields history, should be taken into account when assessing the risk to a group of lambs.
“South-facing fields tend to have an earlier hatch and, as a guide, every 100m increase in altitude will delay hatching by about seven days. So if the nearest weather station on the interactive map is at 200m above sea level and the farm is 100m above sea level, hatching could be around seven days earlier than our forecast.”