Effects of Dietary Composition on the Rumen Papillae Tissue Proteome of Cows by the Combination of Two-dimensional Gel Electrophoresis and Mass Spectrometry
Abstract：The rumen serves as the primary site for digestion feed and absorption of nutrition, which is the characteristic unique organ presented in ruminant animals. To investigate the changes of rumen papillae proteome affected by dietary change, in the current study, twenty-four primiparous Holstein cows(Bos taurus) with similar day in milk and body weight were randomly assigned to 2 treatments (12 cows fitted with rumenal cannulas). 1) cows were fed high concentrate diet consisted of corn(Zea mays) stalk and concentrate; 2) cows were fed low concentrate diet consisted of Chinese wildrye(Elymus chinensis), corn silage, alfalfa(Medicago sativa) hay and concentrate in a 4-wk trial. Rumen papillae was collected from ventral rumen wall of cows after a 4-wk trail. Alteration of protein were detected and identified using two-dimensional gel electrophoresis in combination with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results showed that acyl-CoA synthetase family member 2, hydroxymethylglutaryl-CoA synthase, peroxiredoxin-2 and voltage-dependent anion-selective channel protein 1 were upregulated in response to high concentrate diet, while keratin 6A and larva-specific keratin(RLK) were upregulated in response to low concentrate diet. The identified proteins were mainly associated with functions related to stress, metabolism, and signal trasduction. Based on these findings, it was concluded that the changes of rumen papillae proteins affected by dietary composition that mediate rumen epithelial adaptation to dietary change
