Immunoglobulin concentrations in serum and nasal secretions of calves at the onset of pneumonia

Immunoglobulin (Ig) concentrations in serurn and in nasal secretions were correlated with pneumonia and diarrhea during the first 12 wk of life of dairy calves. The peak onset of pneumonia occurred between 2 and 4 wk of age when the calves\u27 serum Ig G1, Ig G2 and IgA concentrations were lowest. As IgG2 concentrations increased, fewer calves developed pneumonia. Peak onset of pneumonia was also correlated with the lowest IgG and IgA concentrations in the calves\u27 nasal secretions. Diarrhea often preceded pneumonia.; Dairy Day, 1984, Kansas State University, Manhattan, KS, 1984