Zinc oxide ban increases antibiotics use on Danish pig farms

The 2022 ban on zinc oxide use on Danish pig farms has been followed by a sharp increase of antimicrobial use (AMU) on holdings, a study by Denmark’s National Food Institute has revealed.

The study, due to be published in the July issue of Preventive Veterinary Medicine, found that AMU in weaners increased by 17% on farms that had previously used zinc oxide, and even farms that hadn’t used it saw a 19% rise.

The survey covered between 45% and 70% of all Danish weaner pig farms, and up to 94% of finishing units.

See also: Antibiotics resistance reaches 10-year low in food production

Danmap, a Danish surveillance programme for antimicrobial use and resistance, supports the study’s findings, noting a rise in the use of aminoglycosides, especially neomycin and apramycin, which are used to treat E. coli-related diarrhoea, post-zinc oxide.

‘Masking deeper issues’

This increase, the study suggests, indicates wider challenges linked to increased post-weaning diarrhoea and pathogen pressure.

While some farms reported major issues with piglet health, others experienced little to no disruption, highlighting the importance of hygiene, housing, feeding and weaning management.

“Zinc oxide almost acted like a sticky plaster, masking deeper issues in piglet health,” said Nigel Bennet, livestock area manager for northern Europe at biosecurity and hygiene specialist Roam Technology

Now that it was gone, he explained, underlying problems such as post-weaning diarrhoea were surfacing, and “proving difficult to manage”.

“The situation emphasises the urgency of improving non-antibiotic disease control strategies,” he said.

“Controlling it now requires a much more holistic strategy. Hygiene is central to that; from farrowing accommodation right through to weaning accommodation.” 

UK pig industry antibiotics use

Approval for the use of zinc oxide was withdrawn in the UK in 2023, and figures from the AHDB highlight that antibiotics use in UK pigs rose to 85mg/population corrected unit (PCU) in the same year, from 72mg/PCU in 2022, although still lower than 2021 levels.

However, the AHDB’s head of animal health & welfare, Mandy Nevel, said UK pig producers could be proud of their continuous progress, ensuring antibiotics were used responsibly.

“They use as little as possible, but as much as necessary to protect the health and welfare of our animals,” she said.  

While the withdrawal of zinc oxide has presented some challenges for certain units, the industry remains proactive and is working hard to mitigate these impacts.

“The focus now shifts to protecting this momentum, ensuring we do not take our foot off the pedal with biosecurity, hygiene and management, which could allow other pathogens to create problems,” Ms Nevel added.

National Pig Association senior policy adviser Katie Jarvis added: “The UK industry has experienced some disease pressures alongside the removal of zinc oxide and vaccine shortages, but we remain committed to the responsible use of antibiotics and further reductions in usage.”