Pig producers used fewer antibiotics last year – with the amount prescribed falling by 5% on UK farms in 2020 – a total reduction of 62% since 2015.
The decline comes despite disease outbreaks and challenges caused by supply chain disruptions during the coronavirus pandemic which meant pigs spent more time on farm than usual.
Antibiotic use during 2020 reduced to 105mg/PCU compared with 110mg in 2019 and 278mg in 2015, according to data collected using the electronic medicine book.
The book represents more than 95% of pigs slaughtered in the UK and continues the downward trend since recording started – although swine dysentery in 2019 and early 2020 temporarily halted progress.
The overall result is close to the target of 99mg set by the UK pig industry. AHDB pork sector strategy director Angela Christison said the reduction was a good result in a difficult year,.
She said: “The industry understands how important responsible antibiotic use is and that is why there are tough targets and we work together towards them. The sector has delivered sustained reductions since recording began via eMB in 2015.
“This continued improvement, despite disruption to pig flow during the pandemic, is a credit to collaboration between producers, vets and the industry as a whole.”
Usage of the highest priority critically important antibiotics (HP-CIAs) remains at a very low level, although there was a slight increase from 0.04 mg to 0.05 mg. No colistin use has been reported in 2020.
HP-CIAs, as categorised by the European Medicines Agency (EMA), are the most important for human medical health and reductions in their use has been a focus for all UK farm animal sectors since stewardship efforts have stepped up.
Mandy Nevel, AHDB head of animal health and welfare, said: “The EMA advice, which Pig Veterinary Society guidance supports, is that veterinary surgeons should prescribe a lower priority alternative to HP-CIAs unless there is no other option.
“This could explain why, despite the reducing trend overall, we are seeing an increase in use in some lower priority antibiotics such as neomycin.”
Alternatively, these could be short term adjustments as the industry accommodates the phasing out of therapeutic zinc oxide, which treats post-weaning diarrhoea in piglets, said Dr Nevel.
“Either way, while the proportion of these antibiotics being used remains low, as does resistance reported through Government surveillance, we must continue to monitor these trends and work to understand the reasons for changes in their use.”
Collaboration within the industry has been one of the success factors behind the reductions achieved.
The survey allows the industry to look at the more nuanced variations in individual antibiotic use to identify potential reductions.
Dr Nevel added: “The challenges in the industry during the past year highlight not just the importance of this cross-industry approach in our sustained drive for good stewardship, but also the need for antibiotics to safeguard pig welfare.”
Gut health ‘key to reducing antimicrobials’
Low stress levels are key to reducing gut inflammation and the unnecessary use of antibiotics in pigs, suggests a Nuffield study.
“With the ever-increasing pressure to reduce antimicrobials and the looming crisis of antimicrobial resistance, pig producers must review their unit in a holistic manner with gut health at its centre,” says author Heidi Hall.
Ms Hall examined ways farmers can manage herds with minimal requirement for antibiotics. “Harnessing the power of the microbiome, the population of bacteria which reside in the gut, is the key to sustainable pig production.”
She adds: “We need to routinely measure microbiome changes alongside stress levels in animals, prior to and during research trials, so that we can better understand any performance changes seen.”
Medication reduction in the breeding herd was achievable by improving immunity, vaccination protocols and a focus on gut health. This should result in further improvements in progeny performance through maternal transfer.
“We need to further understand the influence we have on gut health through effective monitoring on farm and in trials. We can then look to manipulate gut health to favour a microbiome which is best suited to the production system.”