Evaluation of Changes in Hemato-Biochemical, Inflammatory, and Oxidative Stress Indices as Reliable Diagnostic Biomarkers for Subclinical Mastitis in Cows.

Subclinical mastitis (SCM) is one of the most economically important diseases affecting dairy cows. The purpose of this study was to assess the effect of SCM on selected blood biochemical parameters, with particular emphasis on inflammatory responses and biomarkers of oxidative and antioxidant states. The study was conducted on 50 Holstein Frisian cows classified as 40 SCM and 10 healthy controls depend on California Mastitis Test and somatic cell count in milk. Blood and milk samples were taken for the selected hematological and biochemical analyses. The results showed that the SCM cows demonstrated significant decrease in RBC parameters. Total leukocytic and neutrophilic counts showed significant increase, however lymphocyte count was significantly decreased. Biochemical estimation revealed significantly lower serum values of TP, Alb, Glob A/G ratio and prolactin in SCM cows. However, significant elevations were reported in serum glucose, cortisol, and enzymatic activities of ALP and LDH. Serum values of MDA and NO showed significant increases in SCM cows while, GSH and TAC levels were markedly decreased. The serum levels of inflammatory cytokines implicated significant increases in IL-6 and IL-8 with significant decreases in IL-10 in the affected group compared to controls. The average values of Haptoglobin, Amyloid-A and ceruloplasmin demonstrated significant increases in both milk and serum of SCM cows. All measured acute phase proteins yielded the same sensitivity and specificity. Ceruloplasmin had the highest rate of increase in milk while amyloid-A had the rate of increase in serum. The present study can conclude that APPs, proinflammatory cytokines, and oxidative stress indicators may serve as valuable biomarkers for the diagnosis of SCM in cows. Among APPS, milk ceruloplasmin can be considered the most reliable for detection of SCM, while in serum, amyloid A appeared to be a reliable protein for diagnosing of the disease in cows. [ABSTRACT FROM AUTHOR]