Protein Metabolism and Signal Pathway Regulation in Rumen and Mammary Gland

Protein is an important yet the most expensive dietary component for farm ruminant animals. Understanding the mechanism behind protein utilization in animals for maintenance and milk production is critical for raising animals efficiently. Once the protein has been ingested, it undergoes various transformations in the gut before it is absorbed into blood and its precursors are harnessed by the mammary gland for milk protein synthesis in lactating animals. Several signaling pathways are involved both in absorption and in milk protein biosynthesis. Protein metabolism and signal pathway regulation in various tissues of ruminant are thus reviewed with emphasis on two particular tissues, the rumen and the mammary gland.