Fecal shedding of coliform bacteria during the periparturient period in dairy cows

Objective-To determine whether numbers of coliform bacteria in feces of dai ry cattle changed during the periparturient period and whether fluctuations were associated with changes in dry-matter intake. Animals-12 healthy Holstein cows. Procedure-Fecal samples were collected on a semiregular basis (ie, 3 to 7 t imes/wk) beginning 4 to 6 weeks before the anticipated parturition dale and continuing through the third day (5 cows) or second week (7 cows) after pa rturition, and total numbers of fecal coliform bacteria were determined. Da ily feed intake of 7 cows was monitored. Results-For 11 cows, fecal coliform bacterial counts between 34 and 25 days prior to parturition were low and relatively constant (< 10(2) change in n umber of bacteria). Coliform bacteria were not detected in 4 to 8% of fecal samples from 10 cows. All cows had a 10(4) to 10(7) increase in number of colony forming units/g of feces near the time of parturition. Number of fec al coliform bacteria peaked within 7 days of parturition in 9 cows and with in 12 days of parturition in 3. Number of fecal coliform bacteria was not c orrelated with feed intake. Conclusions and Clinical Relevance-Cows may have large increases in fecal c oli form bacteria count during the periparturient period; however, peripart urient cows do not continually shed high numbers of coliform bacteria, and coliform bacteria may not always be detectable by conventional culture meth ods. Changes in fecal coliform bacteria count did not correlate with change s in dry-matter intake. (Am J Vet Res 2000;61:1636-1638).