Taiwan Provincial Research Institute for Animal Health.
l. School of Veterinay Medicine and Animal Science, Kitasato University. JAPAN 2, Re arch Center for Veterinary Science, The Kitasato Institute, JAPAN
Escherichia coli, isolated from the suckling piglets with diarrhea, were used for vaccine production. The immunity is discussed as follows: The pregnant sows were immunized with the enterotoxins (LT, ST) and vero cytotoxin vaccine or the pili(K88, K99, 987p) vaccine. After farrowing, the suckling piglets were orally challenged with bacterial suspension to detect their protection ability. Besides, several tests were performed: agar gel immunodiffusion tests, to detect anti-LT antibody; piglet loop tests, to detect ST ense materials; and slide agglutination tests, to detect anti-pili antibodies. The results of the experiment indicated that the sows acquired immunity from the enterotoxins or the pili vaccine, and their suckling piglets obtained passive immunity via the colostrum. However, the cross immunization could not be obtained in these two types of vaccines. In practical appl!cation, it is essential for vaccines to be able to produce enterotoxins and pili strains. By virtue of the application of vaccines, the Immunization on both sows and their suckling piglets was considered to be possible and was highly thought of.