Abstract：The liver plays an important role in the regulation of protein metabolism in body. The purpose of this research is to reveal the relationship between protein synthesis and secretion and liver protein metabolism in goats(Capra hircus) under different dietary patterns. Eight healthy mid-lactation goats were randomly divided into two groups, using 2×2 Latin square design with two replications. Dietary concentrate to forage ratios were 4∶6 and 6∶4. Milk samples were taken to measure milk yield and milk protein levels, and liver samples were collected by living donor liver biopsy. The differential expression proteins in the goat liver were extracted and separated by two-dimensional electrophoresis (2-DE) and MAIDI-TOF-TOF. The daily milk yield of high-concentrate group(6∶4 group)was significantly higher than that of the low-concentrate group(4∶6 group, P <0.05), but milk protein content was no significant difference between two groups (P>0.05). The results of proteomics showed that in high-concentrate group(6∶4 group), elongation factor Tu and glutamate dehydrogenase and adenosine homocysteine enzyme involved in protein metabolism had higher expression , while 26S proteasome regulatory subunit 7 and serum prealbumin involved in protein metabolism had low expression. The ability to synthesize small peptide and lactalbumin was decreased in the liver, while the catabolism of amino acids and the role of oxidative stress were enhanced. The liver metabolism had an important influence to milk protein synthesis and metabolism. It was not conducive to synthesis milk protein for lactation goats fed high-concentrate diets because the consumption of amino acids increased and the synthesis of small peptide decreased. So he raw material for milk protein synthetic was consumed too much and its mechanism will be worth further study. The results of this study provided a clue to research the liver impact of milk protein synthesis.
张树坤1,姜雪元2,倪迎冬3,张源淑1,沈向真2. 不同精粗比日粮对泌乳山羊肝脏蛋白质代谢及乳蛋白含量的影响[J]. , 2013, 21(4): 413-420.
2, 2, 2, 2. Effect of Different Forage Ratio Diet on Hepatic Protein Metabolism and Milk Protein Content in Lactating Goat(Capra hircus). , 2013, 21(4): 413-420.
