6 ways to manage antibiotics usage in pigs

Significant efforts to reduce antibiotics use in the UK pig herd resulted in a 75% fall between 2015 and 2022. Since then, however, rates have been increasing again – if only slightly.

In that seven-year period, average usage dropped from 278 mg/PCU (milligrams per population correction unit) to 72 mg/PCU.

The data collected through AHDB’s electronic Medicine Book then showed a small increase, to an average of 85 mg/PCU, in 2023.

This is still lower than the 87mg/PCU recorded in 2021, and discussions continue about the potential to continue the overall downward trend in antibiotics use.

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One of the likely reasons for the slight increase is the ban on zinc oxide in post-weaning diets.

This had helped prevent post-weaning diarrhoea (PWD), says pig vet Dimitrie Leonte, of Garth Pig Practice.

“In 2023, farmers were already reducing or moving away from zinc to start to adapt ahead of the zinc ban, which came into force in summer 2024,” he explains.

“Alternative strategies may not be successful straight away so, until a particular unit gets the right balance of management factors and nutrition, they may need to use antibiotics during the transition.”

Another contributing factor was the surge in cases of swine dysentery reported around the country through the Significant Diseases Charter.

“Swine dysentery is still around,” says Dimitrie.

“The bacteria Brachyspira hyodysenteriae can be brought on to farm through contaminated materials or purchased livestock, so we can work to reduce it through a focus on correct, consistent biosecurity.

“The 2024 figures have yet to be published, but I’m afraid we will probably see another increase – though I hope it will be only relatively small, as in 2023.”

Dimitrie believes the UK can go further in reducing antibiotics use beyond 2022 levels, though by how much is hard to predict.

“Antibiotics are still an important solution. If they are needed to preserve the welfare and health of the animals, their use shouldn’t be overlooked,” he adds.

Minimising the need for antibiotics is down to a combination of management factors and requires a joint effort between the farmer, vet and nutritionist.

The root cause of health, welfare and performance problems is not always an increased or new disease challenge.

Below, Dimitrie highlights the key areas for pig farmers to focus on.

1. Biosecurity

Biosecurity should be a top priority to keep out infectious diseases and maintain established and stable health status.

Measures should include strict pig-free policies for visitors, minimal access for vehicles, cleaning and disinfection of wheels and footwear, vermin control and isolation protocols for bought-in stock.

Internally, thorough cleaning and disinfection of pig pens and equipment must also be carried out consistently, to help reduce burden and spread of pathogens between groups of pigs.

2. Nutrition

Nutrition plays a critical role in maintaining gut health and, therefore, overall pig health, particularly in the first three to four weeks post-weaning, given the zinc ban.

Reducing protein levels in post-weaning diets might help reduce the risk of scouring and gives the pig time to develop a healthy and mature gut.

“This could mean sacrificing a degree of daily liveweight gain for a short while, however, growth rates do catch up, and pigs reach target sale weight in the same time period as before, from what I’ve seen lately,” says Dimitrie.

“Feeding routines or systems may also need adjusting.

“On one breeding unit, we were seeing a persistent issue with looseness in weaners during the first four weeks post-weaning, despite its high health status.

“Extensive testing ruled out a disease challenge, so we looked at nutrition.”

The producer and Dimitrie worked with the feed company to adjust the composition of the first two creep feed rations.

They also found the amount of water being mixed with the dry feed just before consumption was too high.

Piglets were eating a “soup” with a high concentration of minerals, and leaving the cereal portion until later, leading to an overloaded gut.

Through a trial period of weighing feed and calculating different proportions of water they established the right feed consistency.

Incidence of looseness is now very low.

Wean-to-finish mortality has reduced from 4.2% to 1.8%.

Growth rates have increased from 485g/day to an average of 610g/day during the first 10 weeks post weaning, and from 897g/day to 1,105g/day between 30kg and finishing at 110kg.

3. Data gathering and analysis

Routine recording and use of physical performance data, whether automated or manual, is essential for producers to track variations, help identify any hidden issues or follow the impact of planned changes.

Sharing the data regularly with the vet and other farm advisers will help provide a full picture of the farm’s situation.

“For some farms, being in touch for their quarterly vet visit keeps me up to date, while for others, it might be weekly, fortnightly or monthly updates on what is happening on farm,” says Dimitrie, who can help link performance back to any changes introduced.

Vets can also co-ordinate with nutritionists, including joint farm visits.

4. Training and protocols

Good people management and well-established protocols for farm tasks, including regular training for stockpeople and managers, are key to successful pig management.

When staff have the opportunity to join in discussions during vet visits, it improves both their and the vet’s level of understanding.

It also gives staff greater acknowledgement and makes them more receptive and motivated, Dimitrie says.

Producers can enrol staff on industry training courses such as the AHDB’s Stockperson Development schemes.

They can also ask their vet practice to tailor training sessions to specific areas of the business they are focused on improving, such as heat detection or farrowing house management.

5. Vaccination

Targeted vaccination programmes, devised by the unit vet following extensive testing, play a key role in preventative health management in breeding herds.

Strong, healthy sows are the starting point for strong piglets at weaning and good results in the growing herd.

Following the zinc ban, vaccination at weaning or post-weaning is another option to help to protect against PWD-associated pathogens, and its use has increased, although it contributes to higher production costs.

6. Pen layout

Pen layout, pig flow and access to feeders and drinkers can also have an impact on pig health and welfare.

For example, one 5,500-place finisher unit on a continuous flow system had an ongoing problem with Actinobacillus pleuropneumoniae and average annual antibiotics use was between 300 and 400 mg/PCU.

There were also issues with vice.

The producer managed to fully depopulate the buildings and followed a cleaning and disinfection protocol twice, to break the cycle of re-infection, says Dimitrie.

Before restocking, they also amended the pen layout by moving the feeders and drinking lines outside the bedded area.

As a result, there is less pig traffic within the pens, with clear lying, feeding and dunging areas.

Vice outbreaks are now rare, antibiotics use has reduced by 90%, and pig mortality is 75% lower.