A POWYS beef and sheep farmer has adopted stringent quarantine measures to minimise disease and parasite risks when introducing new stock. John Yeamans, with his wife Sarah and sons, runs a closed flock of 720 Beulah ewes and a herd of Limousin cattle on their 110ha farm. New animals are only introduced as bulls or rams, and each undergoes thorough treatment upon arrival.

“The risk is too great not to have a stringent quarantine procedure in place,” says John.

New rams are separated for three weeks and treated for worms, lice, scab and foot issues. This includes an injectable for scab and lice, a clostridial vaccine, foot dipping, and the Group 5-SI wormer Startect.

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Worm control is integral to flock health. Sarah regularly takes faecal egg counts (FEC) and follows a worming plan based on lamb growth.

Lambs are weighed every four weeks in spring and summer, increasing to biweekly after weaning. Any lambs falling below the target weight gain of 200g per day are wormed if necessary.

The only wormer routinely administered to all lambs is Startect, which John uses as a knockout drench during the late summer to eliminate any resistant worms.

John says the impact of this approach is twofold. “First, we see an improvement in growth rates as the surviving resistant worms are removed. Secondly, by eliminating more resistant worms, there is a greater dilution effect on the pasture, which delays resistance development on the farm.

“This helps maintain the effectiveness of wormers for longer.”

In 2021, the benefits of this approach were highlighted when lambs from one hill block were treated with the drench.

In that group only 13% failed to meet the 200g per day growth target six to eight weeks later.

“By using the drench we are able to maintain growth rates and reduce the need for any further treatments,” he adds.

The Sustainable Control of Parasites in Sheep (SCOPS) recommends using Group 4-AD or 5-SI wormers at key points.

Firstly, as part of their quarantine treatments for all incoming sheep, and secondly, as a one-off targeted treatment for lambs, in the latter part of the grazing season.

Zoetis Vet Patricia Van Veen advises that group 4 and 5 wormers should be used when bringing in new stock to target any worms those animals might carry, including resistant worms and parasites not yet present on the farm, such as haemonchus.

“Farmers should not hesitate discuss with their prescriber when to use novel wormers like Startect as a knock-out or quarantine dose, as failing to do so now could contribute to the development of resistance, further complicating worm control efforts in the long term,” she adds.