The objective of this study was to screen and identify differential proteins in the urine samples from cows with fatty liver disease (FLD) in order to provide new biomarkers for FLD. In this trial, twenty urine specimen were collected and assigned into two groups. After labelling with an i-TRAQ reagent, differential proteins in the urine samples were separated using two dimensional chromatography, and then identified by tandem mass spectrometry. The results showed that 110 differential proteins were screened: 50 were upregulated and 60 were down-regulated in the urine of cows with FLD. Among of these proteins, vitronection (VTN), neutrophil gelatinase-associated lipocatin (LCN2), prothrombin (F2), and clusterin (CLU) were the key regulatory factors determined by gene function, signaling pathway, and gene networks analysis. So, it is believed that the 4 key regulatory factors may become important biomarkers of FLD, which will provide new clinicopathologic insights into FLD in dairy cows.

Key words: Biomarkers, Dairy cows, Fatty liver, Urine proteomics