Submitted to: Feedstuffs
Publication Type: Popular Publication
Publication Acceptance Date: 8/28/1998
Publication Date: N/A
Citation: Wells, S., Cray, P.J., Besser, T., Mcdonough, P., Smith, B. 1998. Dairy producers should be concerned about e. coli. Feedstuffs. P. 18-23
Technical Abstract: As part of the USDA's National Animal Health Monitoring System (NAHMS) Dairy '96 Study, fecal samples from dairy cows across 19 states were collected and sent to USDA's National Veterinary Services Laboratories for testing. The laboratory tested samples from 91 dairy operations (more than 3,600 milk cows and 600 cows to be culled within the subsequent seven days) and 97 cull dairy cow markets (more than 2,200 cull dairy cows). Results showed that, while prevalence of fecal shedding of verotoxogenic E. coli 0157 in dairy cows at a single sampling was low (0.9% of milk cows and 2.8% of milk cows to be culled within the subsequent seven days). Prevalence across operations was higher. At this one-time sampling, 24.2% of operations and 30.9% of markets had at least one culture-positive cow. In the NAHMS Dairy '96 study, fecal samples were collected over a six- month period from February through July 1996. A clear seasonal pattern of E. coli 0157 shedding was noted. More than half of the herds tested on or after May 1 were culture positive, compared with very few herds sampled before May 1. Additionally, milk cows, other cows to be culled within seven days and culled cows at markets sampled on or after May 1 were more likely to be culture positive than those sampled before May 1. These results are consistent with other studies of cattle shedding and parallel the trend in reported human E. coli 0157 disease.