Effect of orally administered duodenal fluid susceptibility of newborn calves to an Escherichia coli challenge.

This study was to determine if duodenal contents inoculated orally could alter symptomatic diarrhea produced by Escherichia coli [09:K(A)] in neonatal calves. Inoculum was obtained 2 h postprandially from duodenal-cannulated milk-fed calves. Thirty Holstein bull calves obtained within 3 h of birth were assigned alternately to a 3 X 2 factorial experiment. Calves received either 1) no E. coli challenge, 2) challenge at 12 h, or 3) challenge at 24 h each with or without 200 ml duodenal fluid orally with the first feeding of colostrum. Rectal temperature, urine output, milk intake, and fecal dry matter were recorded daily, and body weight and hematocrit every 3rd day for 1 wk. Gamma globulin of serum was determined at 2 h of age. Inocula and duodenal tissue and fluid of the last 12 calves were assayed for total anaerobic bacterica, anaerobic and aerobic lactobacilli, coliforms, and total aerobic bacteria. Inoculated calves exhibited lower incidence of diarrhea, greater urine output, lower hematocrit, and superior average daily gain as compared to uninoculated calves. Concentration of gamma globulin in serum of inoculated calves was subnormal. Bacterial populations of tissue and fluid at 7 days were not influenced by treatment.