Danish experience in PRRS control can benefit NI pork producers

Wednesday, 30 January, 2019

UFU Watch Commoidty Watch - Written By Policy Officer Dr Geoff Thompson

Several members of the UFU’s Pork and Bacon committee recently visited Denmark to gain first-hand experience of control initiatives to address Porcine Reproductive and Respiratory Syndrome (PRRS). PRRS (or Blue Ear disease) affects both breeding and finishing herds and can have a devastating impact on commercial pig farms, resulting in reduced pig performance and ultimately profit. PRRS is an extremely difficult disease to control. However, the Danish experience has shown that it is possible to control and eradicate the disease from both individual herds and local regions when there is a combined effort by both producers and vets.

In Denmark, a method known as ‘load, close, and expose’ combined with stringent biosecurity protocols is used to eliminate the virus without incurring the substantial financial losses associated with traditional herd depopulation and repopulation methods. The process involves ‘loading’ the breeding herd with gilts before ‘closing’ the herd to new animals. At this stage, the herd is uniformly ‘exposed’ to the virus (usually via vaccination). This process is combined with the ‘10 Golden Rules’ of the Management Changes to Reduce Exposure to Bacteria to Eliminate Losses (McREBEL) system in order to reduce the spread of PRRS and secondary bacterial infections amongst farrowing houses and nursery pigs. Whilst the McREBEL system is extremely effective in reducing and controlling various diseases, it can be difficult to implement as some farms are unwilling to take the robust steps necessary for it to be most effective. However, the Danish experience has repeatedly proven that where people are willing to put in the effort, this process is successful in controlling and eradicating the disease both on individual farms and in some small geographic regions.

10 Golden Rules:

  1. Only cross foster piglets when necessary as protection against infection is best when pigs remain with their mothers.
  2. If cross fostering cannot be avoided, it must be done within 48 hours of birth.
  3. Avoid handling pigs from different litters as this can transfer infection.  Similarly don’t use the same equipment with different litters unless it has been thoroughly disinfected.
  4. When vaccinating or treating pigs, change needles between litters.  Piglets which are unwell should be treated last in the litter.
  5. Sick pigs should remain with their mother and never be fostered off.
  6. Wean all piglets from a batch at the same time and never foster small piglets back to the next farrowing batch. Also, weaned pigs must be moved to the flatdecks and not left in the farrowing room after weaning.
  7. Operate a strict all-in / all-out system in farrowing rooms.
  8. After weaning, pigs of different ages must not be mixed. This includes housing pens of pigs of different ages in the same airspace.
  9. There must be no contact between sows and pigs up to six months of age. This is perticularly relevant to replacement gilts.
  10. Before entering the breeding herd, replacement gilts must be isolated and vaccinated. This applies equally to purchased and home reared animals.

As part of the tour, the group visited a 2,200 sow farm that had successfully eradicated the disease. Prior to control, the farm had been suffering from PRRS type 1 and was experiencing 14% mortality at farrowing. However, as a result of the intervention, the producer was able to eradicate the disease and saw a 20% increase in kilograms per pen per year and on farm income increased by around €4 per pig.

In coming months, Pig Regen will be conducting PRRS sampling for the NI pig industry, and producers should be encouraged by the experience and success in Denmark that PRRS control and eradication is possible where producers are willing to make the effort and seek appropriate advice and expertise from their veterinarian.

10 Golden Rules