Serum immunoglobulin concentrations in response to injectable immunoglobulin in neonatal dairy calves

Thirty Holstein bull calves were used to investigate the use of an injectable solution of purified immunoglobulin (Ig) to increase serum Ig in neonatal calves. Immunoglobulins were obtained from bovine abattoir blood separated and purified by sodium polyphosphate precipitation followed by an ammonium sulfate precipitation. Calves were blocked by date of birth and assigned randomly to treatment within block. Treatments were subcutaneous injections of .9% NaCl without colostrum feeding, Ig (30 mg of Ig/ml) in Lactated Ringer's Injection without colostrum feeding, Ig (30 mg of Ig/ml) in .9% NaCl without colostrum feeding, Ig (60 mg of Ig/ml) in .9% NaCl without colostrum feeding, and injection of .9% NaCl with feeding of 4 L of pooled colostrum by 24 h of age. All calves were injected by 24 h of age. Mass of Ig injected was 1.05 g/kg of body weight. Calves receiving colostrum were fed 2 L of pooled colostrum as soon as possible after birth and at 12, 24, and 36 h of age. All other calves were fed commercial milk replacer in the same manner. Blood was sampled at 0, 48 h postinjection, and 28 d of age and serum was analyzed for IgG and IgM by radial immunodiffusion. Mean serum IgG and IgM in calves injected with Ig were 4.2 and .7 g/L, respectively, and were higher than in calves receiving no Ig. Mean serum IgG and IgM concentrations in calves fed colostrum were higher than in other calves and were 14.6 and 1.0 g/L, respectively. Two calves died during the study. Subcutaneous Ig increased levels of serum Ig, however, further research is needed to accurately delineate optimal amounts of Ig to infuse.