Plasma proteins and a probiotic as ingredients in milk replacer.

Milk replacers containing all milk protein, 25% of protein from porcine plasma protein, 25% of protein from bovine plasma protein, or all milk protein plus probiotic were compared in a 6-wk experiment using 120 Holstein bull calves approximately 7 d of age. All replacers contained an antibiotic except the one that contained probiotic. Calf starter always was available, and calves were weaned when they consumed 680 g/d of starter. Ten calves were selected randomly from each group for sampling of jugular blood at d 1 and 10 of the experiment. A complete blood count was conducted on the samples, and protein fractionation by electrophoresis was performed on sera harvested from the samples. Mean BW gains started to differ at the end of wk 3, and by the end of wk 6 the difference of 2.6 kg was significantly greater for those calves fed porcine or bovine plasma than for calves fed all milk protein (with or without probiotic). The same response was noted for starter consumption; the difference increased to 4.15 kg by the end of wk 6. Most measurements of blood did not differ by treatment; those that were different did not suggest an apparent difference in performance response. Growth performance of calves fed probiotic was not different from that of calves fed antibiotic when both replacers contained all milk protein. Either porcine or bovine plasma protein was an acceptable source of protein.