Animal Industry Report

Extension Number

ASL R2442



Summary and Implications

The occurrence of bovine enteric pathogens and fecal coliform contamination in streams of 13 Midwestern cow/calf pastures was studied during the 2007-2008 grazing seasons. Water samples (n=812) were collected biweekly at up- and downstream locations on each stream. Incidence of Bovine Enterovirus (BEV), Coronavirus (BCV), and group A Rotavirus (BRV), and concentration of fecal coliforms (FC) were evaluated. The mean incidence of BEV, BCV, and BRV in all samples were 5.42, 1.60, and 0.25%, respectively, over the two grazing seasons. There were farm differences for BEV (P=0.02) and BCV (P=0.01) incidences, but there were no differences (P>0.05) for the incidences of the viruses between samples collected from up- or downstream locations. Cattle presence in the pasture on the day and three days prior to sampling were related (P=0.02, P=0.04), respectively, to BEV, but were not related (P>0.05) to BCV or BRV. However, incidences of BEV, BCV or BRV were not related (P>0.05) to cattle presence seven days prior to sampling. Mean FC were 930 and 938 colony-forming units (CFU)/100ml, respectively, for up- and downstream samples. Differences (P=0.01) were observed between farms for concentration of FC. Preliminary results indicate that the timing and management of grazing may be beneficial in decreasing the incidence of enteric viral pathogens and concentrations of FC in Midwestern pasture streams.

Copyright Holder

Iowa State University