Abstract: The risk that the health of pregnant animals and their young will be impaired by gastro-intestinal infection is reduced by oral administration of endotoxins of the relevant pathogenic organisms to the pregnant animals. Combination of oral and parenteral administration is particularly beneficial, whether the animal is pregnant or not, in boosting immunological capacity. This technique is especially beneficial for mammals whose young acquire their passive immunity via the colostrum and hence through the gastro-intestinal wall, such as pigs, cows and sheep.

Abstract: A vaccine comprising an antigen selectively adsorbed onto erythrocytes possessing their natural surface characteristics. When the antigen is the K88a,b/adhesion factor of E. coli and the erythrocytes are chicken erythrocytes, the vaccine is especially suitable for reducing the incidence of neonatal diarrhoea in pigs if it is administered parenterally to a sow about three weeks prior to parturition.

Abstract: To improve the resistance of pigs to gastro-intestinal disorders, the endotoxins of one or more of the pathogenic E. coli serotypes C8, 045, 0138, 0139, 0141, 0147 and 0149 are introduced into the pig intestine. Administration, which may for example be in water or in a pig feed, stimulates the pig intestine to produce antibodies to the E. coli organisms.