Reduced antibiotic consumption in Danish pig production yields positive results

Baldershave | Danish gestating sows loose, housed on solid floors in straw bedding.

Adoption of rigorous husbandry protocols effective in cutting post-weaning mortality in swine

Back in the 1960s and 1970s, when pig production started to intensify, producers in many countries used the easy way out to control disease problems in their pigs, by simply medicating feed with cocktails of various antibiotics. The Danes have always had a responsible attitude to pig production and, with respect to medication, were even very careful about what went into their pig feeds 50 years ago. Furthermore, researchers wishing to medicate feeds had to have their protocols cleared at the highest level.

In the mid-1960s a German producer, Heinrich Biel, devised a pig-rearing system which, bizarrely, involved buying in two-day-old piglets, artificially rearing them in tiered cages and feeding them liquid diets. The author was a research student in Denmark at that time carrying out a similar project, but not with piglets in cages. The piglets in this trial were fed liquid skimmed milk and, to prevent disease, the protocol required including: Aureo SP 250-100ppm Aureomycin, 100ppm Streptomycin and 50ppm Penicillin in the feed. This "cocktail" was unheard of in Denmark ,and it took a lot of persuasion to get the protocol approved by the research chief.

Moving on, there had been concerns for many years in Denmark about antimicrobial resistance and threats to human health, so the Danish Integrated Antimicrobial Resistance Monitoring and Research Program (DANMAP) came into being in 1995, established by the Danish Ministry of Food and Health. DANMAP reports are published in Danish and English, each year, each a substantial publication by any standards and accessible free of charge on the Internet.

DANMAP/Vetstat tracking

All pig farmers are listed in the DANMAP/Vetstat database in terms of their unit's consumption of antimicrobials. Significantly, all the vets are also listed showing the amount and type of drugs that they prescribe. Data is extremely detailed, showing the exact amounts of antibiotics prescribed monthly for different disorders and by category of pig. Individual herd data can be compared to national and regional data sets, etc. Another feature of Danish production is that farmers get a prescription from their vet, which is then taken to the local pharmacy for dispensing.

In the early 1990s antimicrobial use, prescribed and antibiotic growth promoters (AGP) in the Danish industry was steadily increasing and hence, a ban on giving AGP to finishers was introduced in 1998, resulting in a drop in total microbials used in 1999. This was short lived as the amounts of prescribed antimicrobials increased through the early 2000s. Antimicrobials consumption steadily increased through to 2009, which was causing concern. Although, pig production nationally was increasing so it could be argued that consumption per pig was not increasing, just that a larger pig herd would need more antimicrobials, simply because of the increased number of pigs.

The increased amounts of antimicrobials being used caused considerable concern, and so in 2010, the Danish authorities introduced the "Yellow Card" scheme to decrease antimicrobials usage. In addition, in 2010 the use of Cephalosporins was banned. Threshold limits for antimicrobial use for sows, weaners and finishers were introduced which, incidentally, were being exceeded by around 10 percent of producers.

Card system works

In July 2010, letters were sent to 1,249 producers who were close to or exceeding the permitted levels. Producers had the chance to challenge the data relating to drug use on their units before government legislation was enacted later that year.

Roughly half those producers were within the limits, but 500 producers were not and hence received an unwelcome yellow card. The consequences of the card are that the herd is audited for nine months -- plus the antibiotic use on the farm must be reduced to below the permitted levels. The yellow card status is re-evaluated after nine months. A negligent producer may be given a red card and, in this case, producers may have to reduce stocking rates which effectively reduces antibiotic use.

Putting the yellow and red card system in place might be seen as heavy handed and Draconian, but the Danish authorities take the issue of antibiotics very seriously. The yellow card concept has been in place now for nearly three years. Consequently, drug consumption dropped by 20 percent in 2011, with water medication showing the biggest decline. In 2012, overall consumption levelled out, although there was a 5 percent spike in January 2013. Reasons for this are unclear.

In contrast to the downward trend in microbials consumption, the use of vaccines has increased between 20 and 30 percent. Denmark didn't suffer as badly as England did with Post-weaning Multisystemic Wasting Disease (PMWS) and this is reflected in the relative Porcine Circovirus Type 2 (PCV2) vaccination rates, with English levels being more than double than the Danish ones.

Dr. Margit Andreasen stated that the lowering of microbial use was due to the following factors:

1. The unique Danish Specific Pathogen Free (SPF) health management system
2. High levels of management
3. The Danish co-op system
4. The immediate application of new production technology
5. Vaccination strategies
6. Eradication programs

Future progress

Looking ahead, there are several political initiatives in the pipeline, to further reduce microbials use, such as new taxes on broad-spectrum antimicrobials; elimination of vaccine taxes; the restricted use of oral medication; frequent veterinary visits; and regulatory lab diagnostics. While these initiatives may not benefit Danish producers financially, they will produce a better public image in the press and with Danish consumers.

The Danish pig industry takes a great pride in developing new initiatives within the EU. In this context, Brussels is looking very closely at the DANMAP/Vetstat initiative as a blueprint for other EU members, so yellow cards might soon be appearing all over the EU and not just in Denmark.

According to Dr. Andreasen, the Danish SFP system positively impacted the health of the Danish pig herd, and this concept is being promoted in Denmark with these herds naturally being far healthier than the average Danish pig farm. In fact, 70 percent of Danish sows are in SPF herds and 90 percent of sows in Danbred nucleus and multiplier herds are covered by the SPF system (SPF-Danmark).

PMWS Crisis

In the early 2000s, when Europe was ravaged by PMWS, pig herds did not respond to antibiotic treatment and producers suffered huge post-weaning losses. (At this time, Circovirus vaccines had not yet been developed.) In France, PMWS wreaked havoc to such a huge extent that French research scientist Dr. Francois Madec was threatened with being fired if he failed to come up with a solution. Madec kept his job as he formulated the famous 20-point "Madec Plan." The key points were minimizing stress, breaking pig contact by moving to all-in all-out systems, moving to batch farrowing (as opposed to farrowing weekly) and meticulous disinfection of buildings, including emptying and disinfecting slurry pits. 

A maximum pen number of 13 pigs per pen, reducing mixing, feeding better quality feeds and running barns at higher temperatures were other points in the Madec Plan.

Pigs were given lots of care to keep the syndrome at bay. The Danish pig herd also suffered from PMWS, but not to the same degree as the UK -- mainly due to the higher standard of buildings which made power washing and disinfecting much more effective.

Mixing and matching

That old saying "you look after your pigs and they'll look after you" is as true today as it was in days of old. History has shown that a high degree of management is effective in keeping pigs healthy, but often human nature is such that, instead, management resorts to delving into the unit drug cupboard or fridge. The Danish yellow and red card system -- plus taxing antibiotics -- made producers re-visit how they rear and look after their pigs. In the past, it was possible to treat disease and poor husbandry by blanket medication. With a limited number of drugs now available and the huge cost of R&D to bring new microbials to the market, we have to take a much more responsible attitude to the use of antimicrobials, plus similar results, in terms of acceptable performance, in many cases, can be obtained by adopting higher levels of pig management.

With European Antibiotics Awareness Day looming, British Pig Executive (BPEX) pig specialist Helen Clarke's comment sums it up nicely: "With all antibiotics, the simple rule is as much as necessary, but as little as possible."

Margrit Andreasen, DSM | Antibiotics use in all Danish livestock shows positive effects of legislation, reducing consumption.

Margrit Andreasen, DSM | The VETSTAT database tracks the veterinary use and distribution of antibiotics in Danish livestock production.

Margrit Andreasen, DSM | This graphic shows the "Yellow Card Effect" and net reduction in Danish antibiotic use.

Edit note: This report was based predominantly on a paper presented by Dr. Margit Andreasen, Boehringer Ingleheim, Denmark, at the 2013 DSM Monogastric Conference, Morley, Derbyshire, UK.

Stuart Lumb has over 40 years of experience in the livestock industry. He travels worldwide, visiting farms and feed mills for stories plus reports on major trade fairs. Stuart Lumb is a UK-based freelance writer. He can be reached at stuart@lumb.karoo.co.uk.