Sheep farming


Sheep farmers can now see first-hand the cost of using the wrong wormer on their farm thanks to a free app and online tool. 

The Sheep Drench Cost Calculator will help farmers, in conjunction with their advisors, decide which wormers to use on their farm. The app demonstrates the potential loss in growth rate, labour and medicine costs when the wrong product is used and conversely, the production improvements when appropriate decisions are made


App screenshot 

Every farm has resistant worm populations which are naturally occurring in the environment. Anthelmintic resistance affects productivity; reduced drench performance means increased surviving worm burden, leading to reduced lamb performance.

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The calculator uses the latest UK resistance data or bespoke farm data so farmers can create specific drench plans with costs and return on investment information.  

Although some wormers may be more expensive, the effectiveness against worms is likely to be higher because there is reduced resistance.


Effectiveness of wormers

For example, a white wormer may only have 50% efficacy and a yellow wormer, 65% efficacy, compared to a clear moxidectin type wormer (milbemycins), which is often greater than 95% efficacy.

The effectiveness of wormers will differ from farm to farm. Farmers that have done faecal egg count reduction tests on their farm and know the effectiveness of wormers can input their own data into the app.

Wormers that are more effective can sometimes be more expensive, but when you are buying a wormer that isn’t that effective on your farm, it’s not just the cost of the wormer that you are losing, but production losses too, which often vastly outweigh the extra cost of the wormer.

Sheep farmer Tom Carlisle, Coxons Farm, Cracoe, Skipton, is lambing 500 Texel cross Mules. He had used the app and was shocked by the potential loss in production by using the wrong wormer.  He found that by doing something as simple as changing a wormer, it was surprising how much money could be saved for the duration the lambs are on pasture, even if it means paying more for the wormer


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Increased profits

For example, in a group of 40 lambs grazing pasture for 120 days, and averaging £2 a kilo, if a white wormer at 50% efficacy was used, then the total cost of lost production compared to a drench with 100% effectiveness was £131.62.

This is in comparison to £13.51 when a clear drench with 95% effectiveness was used, so moving to a more efficacious drench gives a big potential return on investment.

The app can be downloaded from the Apple App Store or Google Play Store and is free of charge.

Google storeApp store logo


1. WAARD Project Final Report. Sept 2015.


For further information, please see the product SPC, or contact your veterinary surgeon, SQP or Zoetis UK Ltd, Walton Oaks, Dorking Road, Walton on the Hill, Tadworth, Surrey, KT20 7NS. Customer Support 0845 3008034. . Always seek the advice of your medicines provider. Use medicines responsibly ( AH335/17