Suckler and beef farmers were told that resistance to wormers is growing in cattle and that it will be a challenge in the not too distant future at an Animal Health Ireland (AHI) weanling health event on Wednesday.

The event took place at Ennis Mart.

AHI’s beef health check and parasite control programme manager Dr Natascha Meunier said that the worms the cattle have “become more resistant” to wormers over the years as they are locked in a “survival of the fittest” battle.

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She added that farmers should consider dung sampling and making changes to grazing management to minimise this risk.

Dr Meunier explained how she is always asked what is the best dose to give cattle and she said her honest answer is that it depends on a number of factors.

She explained to farmers at the event how there are only three families of wormers, with three active ingredients.

“While you could have given a different product to the last time, the active ingredient could well be the same. It’s not about the injectable, the pour-on or the drench, it’s about what’s in them,” she said.

“The long-held belief was that you dose your animals and move them to fresh grass, but that’s not the research now. It’s better to dose a few from a bunch that are coughing and leave the stronger ones without a dose for maybe seven days and return them to the same pasture. That way the eggs from the resistant worms are not coming out on fresh grass to live and stay.”

Weather impact

Dr Meuiner explained how with recent warm weather and rain, along with the forecast showing increased rain, will likely cause a spike in weanlings coughing, but she added that this can be unpredictable.

She told farmers that now that the weanling is away from its dam and eating grass that they are developing a worm burden.

“The critical point here is not to allow that burden to develop coming into the housing period.”