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

Keiichi Hisaeda, Naomi Ohta, Naoki Yamamoto, Akira Goto, Yoichi Inoue, Yasunori Shinozuka, Naoki Suzuki, Naoki Isobe

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.