Porcine Circovirus Type 2 (PCV2) is the obligate infectious agent in Postweaning Multisystemic Wasting Syndrome (PMWS) of pigs. To control PMWS we vaccinated dams twice, 4 and 2 weeks before pregnancy and once in the 12th week of gestation with an inactivated PCV2 vaccine (Circovac®). Two producer farms run under the control of Swiss Swine Health Organisation were selected for the experiment. Previously, in one farm PMWS was diagnosed after weaning, whereas in the other farm, pigs wasted during the fattening period. For the experiments 113 dams were randomly vaccinated and 111 dams were sham injected. Vaccination increased serum antibodies in dams 3-9 fold accompanied with serum antibody titer increase in their offspring. In the 6th week of life, progeny from vaccinated dams had about the same IgG antibody titer as progeny of unvaccinated dams at the third day of life. In sera of vaccinated dams only low concentration of PCV2 DNA was detected and no progeny developed PMWS. Interestingly, at day 56 four progeny of unvaccinated dams were tested positive for anti-PCV2 IgM antibodies indicating a primary infection with PCV2. Of economical importance, progeny of vaccinated dams had a significant higher daily weight gain in the fattening period (farm X +51 gr/d; farm Y +30 gr/d) and thus a shortened fattening period of about 6 days compared to progeny of controls. To our knowledge this is the first demonstration of subclinical circovirus infection and its effects on growth performance of fattening pigs by vaccination of dams. Kurmann J, Sydler T, Brugnera E, Buergi E, Haessig M, Suter M, Sidler X; Vaccination of dams increases antibody titer and improves growth parameters in finisher pigs subclinically infected with PCV2; Clin Vaccine Immunol. 2011 Aug 18. [Epub ahead of print]
Department for Farm Animals, Division of Swine Medicine, Vetsuisse Faculty, University of Zurich, Switzerland.
PMID: 21852549 [PubMed – as supplied by publisher]