The interest in research for biomarkers discovery for the diagnoses of bovine mastitis stems largely from the need to better characterize mechanisms of the disease, to identify reliable biomarkers for use as measures of early detection and drug efficacy, and to uncover potentially novel targets for the development of alternative therapeutics. Most of proteomic studies on mastitis have been performed on milk and somatic cells1,2. Differential expression analysis performed from Baeker et al. 2,3 of the whey from both mastitic and non-mastitic milk revealed a marked increase in the expression of a series of some proteins during infection. Although proteomic profile of bovine milk whey proteins have been well characterized limited information has been provided on serum and plasma proteomics of bovine mastitis. The aim of this work is to extend the current knowledge on molecular circulating biomarkers of mastitis including both sub-clinical and clinical animal group. Whole serum proteome was extensively evaluated by three different complementary approaches in the clinical groups in order to possibly find differential protein expression useful to help in early diagnoses of this pathology. The collected evidences showed complementary data between oxidative stress response, lipid metabolism and the differential protein expression.