Graziers warned to assess nematodirus risk as threat rises

Sheep farmers should consider five key factors to gauge nematodirus risk on their holding as the threat of the disease rises across the country, warn livestock advisers.   

This follows disease monitoring updates from across the country, with 29 of 140 weather stations currently at “high risk” or “very high risk”.

The 29 forecasts are mainly across central and southern England and Wales, but also appear as far north as the Vale of York and Strathallen, Scotland.

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High risk

This represents a danger to lambs, both through lost growth performance and potential mortality, says the Sustainable Control of Parasites in Sheep (Scops) group

Many weather stations at higher altitudes and further north and west remain at “negligible” or “low risk”. Farmers should look for risk level at the nearest weather station data by checking the nematodirus forecast.  

Five factors

Scops says the first factor to assess is if lambs are on high-risk pasture – for example, pasture that was grazed by ewes and lambs last spring.

If one or more of the following four factors is present on their holding, farmers are advised to act now (see “Advice on nematodirus”).

• Are lambs old enough to be eating significant amounts of grass? This is generally from six to 12 weeks of age, but can be younger if ewes are not milking well
• Do you have groups likely to have a coccidiosis challenge? For example, mixed age lambs are at highest risk
• Has there been a sudden cold snap followed by warm weather?
• Are lambs under other stresses. For example, triplets, fostered lambs or lambs on young or old ewes.