Lambs should not scour when they are grazing fresh grass, according to Tommy Heffernan, a Wicklow-based vet, who said it is mostly likely as a result of parasitic infection.
Speaking at a recent livestock seminar, attended by over 60 farmers in Aughrim, Co. Wicklow, the vet said there are a number of different parasites that can affect sheep.
But, he said the only true way to identify what parasite is impacting on the lambs performance is through the use of a Fecal Egg Count (FEC).
Fecal egg counting involves collecting a sample of faeces from the lambs and sending it away to a lab to identify the number and type of worm eggs present.
He said that farmers should carry out a fecal egg count on their lambs in the first week of May to identify what worm dose is required.
“There is no perfect answer for treating worms in sheep, but farmers should carry out a FEC every two weeks from May on,” he said.
Heffernan also said that some sheep will not need a worm dose at this stage and the FEC test is the only true way to tell if the lambs need a dose or not.
Sheep farmers are starting to see problems with resistance to wormers, FEC can do two things. It can identify resistance problems and it can also indicate the worm burden of the sheep.
“The problem with FEC is that they are perceived as extra work, but they can provide farmers with an awful of information.
“If farmers are dosing sheep and they are not getting a desired response there may be a problem with resistance.
The vet said that resistance issues can be identified by FEC sampling the lambs both before and after dosing and seeing what reduction in the number of worm eggs occurred.
“They should aim for a 95% reduction in the worm egg count, anything lower is a sign of resistance,” he said.
