Effect of the Timing of Vaccination in Pregnant Sows and Colostral Restriction for Neonatal Piglets on the Level of Transmission of Maternal Antibodies for Classical Swine Fever Vaccine to Suckling Piglets

We investigated the effect of both duration from vaccination to parturition in pregnant sows and colostral restriction during 6 h after birth for neonate piglets on the level of maternal antibodies for classical swine fever (CSF) vaccine in suckling piglets. In this study, piglets delivered from 3 pregnant sows vaccinated with CSF and 2 unvaccinated pregnant sows were used, and the serum CSF neutralizing antibody titeres in piglets with colostral restriction during the suckling period was significantly lower than those without the restriction. In the piglets with restricted colostrum intake, the group with a period from vaccination to parturition of 21 days had a significantly lower CSF antibody titer during the experimental period than the group of more than 161 days. The percentage of piglets testing positive for CSF antibodies was 0% at 14 and 21 days after birth in the group with short a short period (21 days) from vaccination to parturition and colostral restriction. Our results indicate that both of the timing of the initial vaccination of unimmunized pregnant sows and the restriction of colostrum have a clear effect on the level of maternal CSF antibodies in suckling piglets.