The aim of the research reported in this Research Communication was to identify differentially expressed proteins in dairy cows with normal and lutein diet and to elucidate the mechanisms of lutein-induced effects on bovine mammary gland metabolism using a comparative proteomic approach. Thirty-three differentially expressed proteins were identified from mammary gland of control diet-fed and lutein diet-fed dairy cows. Among these proteins, 15 were upregulated and 18 were downregulated in the lutein group. Functional analysis of the differentially expressed proteins showed that increased blood flow, depressed glycolysis, enhanced lactose anabolism, decreased fatty acid oxidation and up-regulated beta lactoglobulin expression were connected with lutein addition. These results suggested that the increased blood flow, reduced glucose catabolism, enhanced capacity for milk lactose synthesis, depressed fatty acid catabolism and increased expression of antioxidantion related protein may be the prime factors contributing to the increased milk production and enhanced immune status in lutein-fed dairy cows. This study provides molecular mechanism of dietary lutein in regulating lactation of dairy cows.
Keywords: Lutein; dairy cows; mammary gland; proteomics.