Haptoglobin and serum amyloid A in milk and serum during acute and chronic experimentally induced <i>Staphylococcus aureus</i> mastitis

TLDR

The study measured haptoglobin and serum amyloid A in serum and milk from infected and healthy quarters of six cows during experimentally induced acute and chronic Staphylococcus aureus mastitis. Haptoglobin and SAA rose rapidly in both serum and milk during the acute phase, remained elevated in milk (and to a lesser extent in serum) during chronic subclinical mastitis, and were specific to infected quarters, indicating that milk SAA could serve as a diagnostic marker.

Abstract

Local and systemic changes in the acute phase proteins, haptoglobin and serum amyloid A (SAA), were studied in six dairy cows during the acute and chronic phases of experimentally induced Staphylococcus aureus mastitis. Haptoglobin and SAA were measured in serum, and in milk from infected and healthy control udder quarters within each cow. Concentrations of haptoglobin and SAA increased rapidly in both serum and milk during the acute phase of mastitis and followed a similar pattern. Significantly raised milk concentrations of SAA were also found during chronic subclinical mastitis. Serum concentrations of SAA also tended to be higher during the chronic phase than pre-infection. Increases in milk haptoglobin and SAA were specific for the infected udder quarters. In conclusion, measurement of SAA in milk samples could be a useful tool in diagnosing mastitis.