Abstract: To investigate the differential proteomic expressions in plasma from healthy dairy cows and clinical mastitic cows, the current research presents the protein changes using two-dimensional gel electrophoresis (2-DE), after the stained with silver nitrate and colloidal coomassie, differential expression proteins were detected by PDQuest 7.4 software and subjected to ion trap mass spectrometer equipped with a Surveyor HPLC system, differential spots of protein were identified. The results showed that 3 protein spots were differentially expressed proteins and identified to be 2 proteins. Overall, haptoglobin precursor was an up-regulated in cows infected with clinical mastitis and could be a mastitis-associated diagnostic marker, while SCGB 2A1 (secretoglobin, family 2A, member 1) was down-regulated protein. There was a significant difference at protein level in plasma from healthy dairy cows and clinical mastitic cows, it suggests that the differential proteome expression analysis of may be useful to clarify the mechanisms involved in the pathophysiology, and to further study of the related proteins and the molecular markers of clinical mastitis.

Key words: dairy cows, clinical mastitis, plasma, proteome