Transmissible gastroenteritis of swine. Efficacy assay of an intramammary use vaccine

Abstract

TGE seronegative pregnant gilts were vaccinated by intramammary inoculations with a chemically inactivated (betapropiolactone) cell culture virus vaccine and their nursing pigs were exposed to virus at three days of age. The pig morbidity and survival rates were compared with those of pigs nursing gilts exposed orally to virulent TGE virus during late gestation and also with pigs nursing non-vaccinated seronegative sows. The morbidity rates were 100%, 19% and 19%, while the survival rates were 33%, 100% and 17% respectively. The intramammary vaccine used to vaccinate pregnant gilts in this study did not stimulate sufficient antibody response to provide an acceptable level of protection to nursing pigs against experimental challenge with virulent TGE virus. The serum, colostrum and milk TGE neutralizing antibody responses are reported.