After a decade of struggle, there is a surge of optimism throughout European pig industries in their long-suffering battle against an epidemic of diseases caused by porcine Circovirus 2 (PCV2) infection. In 2008 there have been significant successes in controlling and preventing the two major disease syndromes associated with the PCV2 virus. These are Post-weaning Multisystem Wasting Syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS).
In the United Kingdom in 2008 there has been a flurry of activity by BPEX Ltd (the non-profit company representing, and disbursing the funds of, pig levy payers in England), The UK Pig Veterinary Society (PVS – representing swine specialist veterinarians) and a number of top farm-animal pharmaceutical companies. Working together, they launched a PCV2 Research Project to measure the improvements in herd health, welfare, mortality and physical performance by unit, region and on a national scale that result from PCV2 vaccination of sows or piglets. Out of this came an advice service on the cost benefits, and optimum approach to using the latest PCV2 vaccines and a 1.5 million GB pounds [$2.3M] project of national mass vaccination of pigs against PCV2 – something that has never been tried before in Britain.
The project began in April 2008 and so far 1.5 million vaccine doses have been funded on 483 pig units with a total of 305,000 sows. This is 75% of the English national breeding sow herd. The preliminary results, based on data from vets responsible for 100,000 sows and 2,000,000 pigs to finish, were reported to a meeting of the PVS last month:
- increased weaned litter size up to half a piglet per litter
- up to 5% lower nursery and 6% lower finishing mortalities
- pigs were more uniform
- pigs reached finished weight up to 10 days earlier
BPEX Director of Pig Industry Development, Mark Wilson commented: "We planned for a nine-month project to end in December [2008], but I am delighted to announce the research project will be extended for another month. The low point in terms of production efficiency was April 2004, with fewer than 17 pigs being sold per sow per year and [only] 1,213kgs of meat per sow per year. However, in recent years, health and therefore productivity improvements have been fantastic due to many factors including the hard work and determination of producers, their staff and vets. There is emerging evidence that PCV2 vaccines and their uptake are having a significant and positive impact on pig health and welfare."
David Burch of the Octagon Services Animal Health Consultancy has carried forward the 2008 BPEX/PVS project with a review of the latest vaccine developments for finishers, sows and piglets, and an optimistic overview of the prospects for finally cracking this epidemic in 2009. Undoubtedly, these PCV2-associated diseases (PCVAD or PCAD) are multifactorial health and performance problems, but PCV2 plays a major role. Burch comments "In spite of the early confusion of the importance of PCV2 in the pathogenesis of PMWS and PDNS, it now can be clearly seen that PCV2 was responsible for causing the overwhelming infection, increased mortality and decreased growth rate and these can be effectively blocked by early piglet vaccination."
The BPEX/PVS and Burch reports, and other related recent PCV2 developments can be viewed in detail at http://www.pighealth.com/circovirus.htm.
Source:
Pig Disease Information Centre, December 21, 2008
Dr. Michael Meredith