Effects of oral antibiotics or bovine plasma on survival, health and growth in dairy calves challenged with Escherichia coli

Thirty-six Holstein bull calves were fed experimental milk replacers (454 g/day(-1)) containing 20% crude protein and 20% fat. Milk replacers contained no additives, antibiotics (800 mg neomycin (as neomycin sulfate) and 400 mg oxytetracycline daily replacing dried whey, or 3.3% spray dried bovine plasma replacing whey protein concentrate. Calves were orally challenged with approximately 10(8) colony forming units (CFU) of enterotoxigenic Escherichia coli on day 3. No veterinary treatments or supportive therapy were provided during the study. Calf body weight (BW) was determined weekly and average daily BW gain was calculated. Clinical scores were determined daily for fecal consistency, attitude and hydration. All clinical scores responded to oral E. coli challenge. Provision of antibiotics and animal plasma had no effect on fecal consistency but improved attitude and hydration scores, body weight gain and tended to reduce overall mortality. Spray dried animal plasma appears to be a viable alternative to antibiotics in calf milk replacer applications.