Vaccination of piglets against post-weaning "E. coli" enterotoxicosis.

E. coli enterotoxicosis is one of the main causes of neonatal diarrhea in piglets. For their protection against this disease a vaccine has been prepared based on K88 and LT. Pregnant sows were vaccinated, thereby transferring passive immunity to their offspring through colostrum and milk. Protection was obtained in terms of decrease in mortality, occurrence of diarrhea and excretion of enteropathogenic bacteria. Piglets from non-immune sows could be immunized shortly after birth. However, piglets from immune sows vaccinated once after birth failed to show an active antibody response; only by two vaccinations, 4 weeks apart, was an antibody formation induced. From the results presented it is concluded that a proper vaccination schedule makes it possible to immunize piglets from both immune and non-immune sows and induce protection against post-weaning diarrhea.