‘Fantastic’ fall seen in antimicrobials use on dairy farms

Total antimicrobials use on UK dairy farms has fallen to 13.7mg/kg population corrected unit (PCU), according to Kingshay’s third annual focus report.

Usage in 2019 was 17.7mg/kg PCU and it then plateaued around 15.7mg/kg PCU. The co-author of the report, Christina Ford, says data to March 2023, gathered from 1,002 producers, shows a further drop.

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“It’s fantastic to see a substantial reduction this year. We found that 67% of our herds were below the 2024 target of 17.9mg/kg PCU,” she says.

This target is based on a 15% reduction on the 2020 target.

The trend follows that of the Veterinary Antimicrobial Resistance and Sales Surveillance 2022 report, which showed UK sales of antibiotics for food-producing animals had fallen by 59% since 2014.

The report also shows that use of critically important microbials has continued to fall and is now at its lowest level, with just 5.7% of herds using them. Of the herds surveyed, 945 have not used them in the past year and 57% have not used them in at least three of the past five years, she says.

Opportunities for improvement

Dr Tim Potter, the report’s other author and senior clinical director at Westpoint Farm Vets, says the data gathered can be used to help farmers change behaviour and adopt better practices, and highlights opportunities to improve their antimicrobials usage.

“The report really helps facilitate discussions with veterinary surgeons and the farm teams [by] looking at how they review their current treatment practices,” he says. “It highlights those specific classes of antimicrobials we’re trying to reduce and allows us to be targeting the areas of highest usage.”

While the overall trend is down, individual results range from 0.04mg/kg PCU to 124.9mg/kg PCU. This is a bigger range than in 2022 and reflects high usage by a single producer dealing with a disease outbreak. However, most producers are using less than 20mg/kg PCU, Christina says.

“No matter what your yield or your herd size, there is variability. It’s not just the high yielders that have high usage, or vice versa,” she adds.

Tim says a more detailed analysis shows that the 25% of farms with the highest use have made the least progress in reducing their antimicrobials usage. The challenge for vets is to support these high users to change practices and learn from the low users to bring down usage, he says.

“We’ve seen significant reductions in the UK dairy sector over the past 10 years and we’re probably now moving into a slightly different phase. It’s now about how to push that further, which potentially is going be harder and will need changes to management and changes to buildings, not just changes in behaviour.

“Ultimately, we’re not looking at zero usage. Antimicrobials remain an essential tool for treatment of bacterial diseases, but it is about making sure we observe best practice.”

Which antimicrobials are most frequently prescribed?

According to Kingshay’s report, injectables are the products used most frequently, with aminoglycosides and penicillin at the top of the list, used by 812 herds.

“For a lot of herds, injectables are big-volume usage now and are the area to focus on if we want to reduce overall usage,” says Tim Potter.

Oral products

One oral product is in the top 10. Although used on only 51 herds, tetracycline, which is licensed for treating calf pneumonia, is in fifth place.

“This really demonstrates the significant impact that oral products have on [overall] usage,” he says. “It contributes a huge amount to usage on farms where it is used, because it is used for group treatment.

“The message is: look at all areas of the farm, not just the milking herd. There’s a real opportunity to reduce oral usage in calves.”