Why planning and patience are the keys to meeting the antibiotic challenge

Good progress has been made in reducing antibiotic use in the pig industry over the past two years.

Figures collected via the eMB-Pigs database show a 35% reduction in usage in 2016, to 183mg/PCU, with further significant reductions expected in 2017. But there is still some way to go to meet the recently set 2020 target of 99mg/PCU.
The Young NPA National event, which took place in London in December, focused on what the industry needs to do get there, highlighting what is achievable but also the potential pitfalls.

Duncan Berkshire, specialist pig vet at Bishopton Veterinary Group, near York, and vice-president of the Pig Veterinary Society, outlined two client case studies where large reductions in antibiotic use were achieved, albeit via rocky roads.

Lessons learned
“It’s a fantastic picture now, but it just shows it doesn’t always work straight away,” Mr Berkshire said, outlining the lessons learned. “We need good diagnostics and early intervention is crucial. Autogenous and commercial vaccines are useful tools, although we do need more help from pharmaceutical companies for further development.

“Hygiene, the environment – buildings and equipment – and staff training are critically important. Depop programmes can help, although they must be planned with military precision. But, however well you plan there is always something that comes along and kicks you in the teeth!
“We need the industry to buy in, and we are getting there. The PVS prescribing principles are an important document, although I am concerned about pig vet shortages, especially with all the uncertainty over EU vets.

“We need alternative options, but antibiotics must remain part of the solution, as there are going to be occasions where we can’t do anything else to ensure the health and welfare of our pigs. We have got to minimise usage but use appropriately.”

Case study 1

This 540-sow indoor breeding unit in Yorkshire finished a third of pigs on site, with the rest going to a nearby grow out farm. It was a continuous flow system, with weaners and growers moving onto the second site, a relatively old building, every week.

Back in 2012, feed medication was being used to control problems like meningitis, joint ills and sudden death. Yet mortality in the grow out was a ‘frightening’ 12%, all in the immediate post-weaning stage, and 5%, and at the similar stage, in the home herd.

Post-mortems pointed to Glässers rather than a Strep-based infection, with hock joints ‘full of gunk’, hearts full of fluid and guts stuck together. “Pigs waste away because it hurts to move or eat – it is a horrible disease,” Mr Berkshire said.

Samples were sent off to the lab and, in the meantime, some immediate interventions were introduced. Medication in feed and water was changed from trimethoprim to penicillin, which can be more effective against Glässers, while the practice of sending the smallest weaners to the grow-out unit was reversed, enabling staff on the home unit to keep an eye on the weaker, more vulnerable pigs.

Mr Berkshire identified the site as an ideal candidate for an autogenous vaccine, that is bespoke for the farm. Glässers is notoriously difficult to grow away from the carcase, however, and it took 16 months and many attempts to isolate it.

The vaccine was introduced at the end of 2013, at which point antibiotic usage was around 250mg/PCU on the two units. With vaccination under way, medication was reduced and by the end of 2014, overall usage had more than halved.

Then, in 2015, enzootic pneumonia (EP) hit with devastating effect, the unit having previously been negative. An EP vaccine was immediately introduced, along with tylosin medication as treatment. The clinical picture remained ‘very poor’ for about a year due to the complicated pig flow – antibiotic use climbed to 365mg/PCU on the source farm and doubled to 200mg/PCU on the grow-out in 2015.

Finally, by 2016 EP was brought under control and the medication could be removed as the EP vaccine had stabilised the herd immunity. During 2016, antibiotic usage dropped back to 2014 levels, and in the first three quarters of this year, hugely impressive figures of 15.3mg/PCU on the source unit and 2.7mg/PCU on the grow out were achieved.

Case study 2
The second example involved a partial de-population at a 600-sow Yorkshire outdoor unit, which had breeding and free range grower sites.
In 2014, it was PRRS negative and EP positive and also had Glässers and Strep-based infections, which were being tackled with creep medication. The weaners were being vaccinated for EP, but there was a problem.

The pigs were on such a heavy contract, some not leaving the site until after 30 weeks, that the vaccine’s protective effect was running out and pigs were breaking down as late-stage finishers and having to be treated to control pneumonia. Because usage was in late-stage pigs, antibiotic levels were high – 628mg/PCU in 2014, a major cost to the producer.

A partial de-population was proposed, medicating and moving the sows and moving all the piglets onto another separate site at the same time. The operation was thoroughly planned, including the relevant EP medication when, two weeks before ‘D-Day’, dysentery appeared in the replacement gilts. With new medication introduced to cover the critical partial de-population period, usage rose to 866mg/PCU in 2015, which is expected when using this type of elimination protocol, Mr Berkshire said.

“If you plan it right, it runs like clockwork. We medicated during the protocol window to improve the herd health status, then removed all medications out of the feed and water. We stopped vaccinating as we also wanted to know if we had eliminated EP,” he added.
“We had no problem with coughing and fantastic growth – and then we got a double whammy of flu and PRRS, which hugely suppresses the pigs’ immune systems. So we started vaccinating again, this time for PRRS.”

The PRRS breakdown put a spanner in the works, with medication still exceeding 360mg/PCU in 2016. But, with all the problems finally under control following the partial depop and PRRS vaccination, medication averaged just 27mg/PCU during the first nine months of 2017.

‘Be proactive rather than reactive’

Producers need to adopt a ‘proactive’ approach to disease control in order to meet the antibiotic challenge, according to NPA senior advisor Georgina Crayford.

Dr Crayford shared some key findings from trips around the world in 2017 for her Nuffield Scholarship into how other countries have reduced antibiotic use and engaged farmers with the issue.

Discussing industry attitudes, she pointed out how certain human diseases, such as diabetes, alcoholism and obesity, had become ‘the norm’, with people noticeably less motivated to address them. Is the same happening with pig diseases, she asked?

Dr Crayford urged farmers to shift from ‘being reactive to proactive’ in their approach, including fully investigating herd health status as a starting point. “Farmers must learn to value vet time and be willing to pay for it. And vets need to get creative,” she said, highlighting vaccination, diagnostics and herd health plans as examples of ‘good use of vet time’.
Citing examples like Denmark, her travels have shown how coordinated Government-industry national health control programmes make a ‘huge difference’ to controlling major pig diseases and reducing antibiotic use.

Addressing the ‘intensive’ versus ‘extensive’ debate, she explained how she had visited very intensive farms in Scandinavia that had achieved huge usage reductions.

Cóilín Nunan, of the Alliance to Save Our Antibiotics (ASOA) insisted, nonetheless, that there was evidence to show a move towards more extensive pig farming would contribute to a reduction in usage. But his claims on this, and particularly the link between weaning age and antibiotic usage, were robustly challenged in a lively panel discussion.

Lizzie Bentley, from the Yorkshire Farmers marketing cooperative, outlined the methods being employed on its farms to reduce antibiotic usage, stressing the need for the entire supply chain to work together and for each individual farm to ‘assess its own starting point and plan and judge progress from that’.
She identified creating breaks to properly wash buildings, biosecurity, diligence in sourcing pigs, breeding, housing, feed, straw and effective alternatives, alongside targeted use of antibiotics, as among the critical factors in reducing usage.