Drench at lambing is most important

EWES SHOULD still receive a worm drench in the time immediately around lambing, despite the temptation to avoid drenching in a bid to cut costs and limit the chances of anthelmintic resistance.

Independent sheep vet Chris Lewis says this dose is the most important one of the year. Around lambing any inhibited larvae leave their winter resting place and move to the gut and produce many eggs. “Knocking out these eggs with an anthelmintic dose is essential to protect lambs from worms.”

The only time when this dose can be omitted is when single-bearing ewes are well fed, says Mr Lewis. “Research has shown these ewes can maintain their resistance even at lambing, so long as they are fed a high protein diet.”

Ian Gill of the Thrums vet group agrees that the lambing dose is the most important, but says it may be possible to use faecal egg counts to check whether ewes need drenching.

Ewes should either be drenched when put into individual pens or when turned out to pasture, advises Mr Lewis.

“When ewes and lambs are kept in for any period of time after lambing they should be drenched when put out to grass. That is providing this is within the period of the peri-parturient relaxation of immunity, which runs for about six weeks after lambing.”