Serum Amyloid A and Lactoferrin Concentrations in Milk at Mastitis Diagnosis Can Serve as a Predictive Indicators of Intramammary Status 7 Days Later

This study investigated whether the inflammatory component levels in bovine milk measured on the day of mastitis diagnosis were associated with recovery outcomes 7 days later. Milk was collected on Day 0 (the initial day of mastitis diagnosis) and Day 7 from 40 quarters of 32 dairy cows diagnosed with spontaneous acute mastitis. The pH, somatic cell count (SCC), and concentrations of serum amyloid A (SAA), interleukin-8, lactoferrin (LF), and sodium in milk were measured on Day 0 to evaluate their association with SCC on Day 7. A positive correlation was identified between SCC on Day 7 and SAA, LF, and Na levels on Day 0. For receiver operating characteristic analysis, a log10SCC > 4.8 (70,000 cells/mL) on Day 7 was considered indicative of mastitis. The cutoff values for SAA and LF on Day 0 were 21.6 and 81 μg/mL, respectively, with sensitivities of 79.3% and 86.2%, specificities of 77.8% and 66.7%, and areas under the curve of 0.784 and 0.762, respectively. These results indicate that measuring SAA and LF concentrations in milk at the initial mastitis diagnosis may predict intramammary conditions 7 days later, potentially aiding in understanding the pathology of mastitis and informing treatment strategies.