Parasite risk at turnout difficult to predict this year

So it’s important to have an understanding of the on-farm situation when planning control strategies.

“There is no uniform approach to parasite control and different systems, operating in different areas of the country will experience varying levels of disease risk,” says Dr Andy Forbes, COWS (Control of Worms Sustainably) technical representative and Honorary Professor at the University of Glasgow’s School of Veterinary Medicine.

“The weather over the winter period is an important factor that can have a significant effect on worm burdens the following season. However, due to the extremely variable conditions observed across the UK this past winter, it’s more difficult to predict the likely threat at turnout this year.

“It’s often thought that a hard winter will kill-off parasites, while mild and warm conditions will see them multiply and thrive. But, this is not always the case. Parasites are effected by the weather in different ways.”

While the weather is an important element that must be considered at a local level, there are several other risk factors to take into account when developing a parasite control strategy.

Dr Forbes explains that compared to beef suckler calves, dairy calves in their first grazing season are particularly vulnerable at turnout.

“As dairy calves will be weaned, their grass intake will be much greater than that of suckler calves, which heightens the risk of them ingesting infectious larvae. Additionally, research has indicated that milk can limit the impact of stomach worms. Dairy calves will no longer have milk in their diet, potentially making them more susceptible,” he says.

“We also have to think about housing periods when determining the level of risk. If cattle have been brought in later in the autumn and turned out earlier in the spring, the residual population of parasites on pasture is likely to be greater than if pastures have been left empty for several months.”

Dr Forbes advises working with your vet, SQP or veterinary pharmacist to plan ahead and implement an effective and bespoke control plan for this grazing season.

“Broadly, there are two options that can be taken to control parasitic worms. One is to treat cattle for gut and lung worms in the early grazing season, to limit pasture contamination and help prevent infection building up later on.

“Alternatively, there is the option to closely monitor cattle through the grazing season for any signs of worm burdens. Ideally, young cattle should be regularly weighed and benchmarked against target growth rates.

“Whichever option is followed, ensure you follow the COWS best practice principles to the most effective use of cattle wormers. Target the animals that are at risk, ensure they receive the correct dose by weighing each animal, and check the dosing equipment,” says Dr Forbes.