Infection with enterotoxigenic Escherichia coli in calves and protection of the calves by vaccination of the dams.

: A report is given of a study on the occurrence of enterotoxigenic Escherichia coli in calves in Denmark. Samples from 1379 1-30-day-old calves were examined and ETEC were isolated from 228 samples (16.5%). While in 1-2-day-old calves nearly one half (47.5%) harboured ETEC, the frequency dropped to 3.4% in 8-day-old calves, and of 165 9-30-day-old calves just one was found to harbour ETEC. A field trial with K99-containing bacterins was performed in 14 herds with ETEC problems. A total of 109 cows were vaccinated with a 4-strain bacterin and 73 with a K99-bacterin, while 114 cows served as controls. Sixteen calves from the 4-strain bacterin group, 6 calves from the K99-bacterin group, and 25 calves from the control group, became diarrheic within their first week of life.