VACCINATION OF SOWS DURING GESTATION WITH A MODIFIED LIVE CLASSICAL SWINE FEVER VACCINE

摘要

In countries endemic for classical swine fever (CSF), the disease is controlled through routine vaccination of sows and piiilcts. In some farms, mass vaccination of breeders that include pregnant sows may be carried out twice a year. Some farmers alsoattempt to boost the levels of maternally derived antibodies (MDA) in piglets via vaccination of pregnant sows. Although a previous study has demonstrated the safety of usinsi I'liSTlFFA* in sows three weeks prior to farrowing (1), it is not known whether there is any validity to the belief that vaccination will boost antibody titres since it is well known that even levels of serum neutralizing (SN) antibodies as low as 1:32 in piglets interfere with the induction of immune response. The present studyaims at determining whether multiple injections of PESTIFFA in pregnant sows would result in boosting SN titres and MDA levels in their litters. The study also examines whether such vaccinations have adverse effects on both sows and piglets.