Seriousness and stability of subclinical mastitis assessed by quarter milk serum albumin

Bovine Serum Albumin (BSA) concentration in quarter milk samples from 51 cows examined twice, at 1½ months intervals, was related to subclinical mastitis diagnoses and to the change in diagnoses from the first to the second examination. The BSA-concentration increased with increasing scores of the California Mastitis Test (CMT). The concentration of BSA was higher if bacteria were isolated as compared to negative bacteriological findings, and it was higher if “major pathogens” (MaP) (Staphylococcus aureus or Streptococcus dysgalactiae) rather than “minor pathogens” (MiP) (S. epidermidis or α-streptococci) were isolated. There was no interaction in the “effects” of CMT-score and bacteria on BSA-concentration. Quarters which were healthy and pathogenfree at first examination and had a non-specific mastitis at the subsequent examination, had significantly higher BSA-concentration at first examination than those which remained healthy. Quarters with non-specific mastitis at the first examination and infectious mastitis at the next examination had higher BSA-concentration at the first examinition than those which turned out with other diagnoses. Quarters with infectious mastitis and MaP at first examination which had a latent infection at the next testing, had a lower BSA-concentration than those with other second examination diagnosis. In general, BSA seems to be a more sensitive parameter than CMT for showing the early establishment of an inflammatory reaction in the alveolar tissue.