Abstract:

With the development of dairy products,milk protein is an important index to evaluate the nutritional value of milk.Optimizing feed formulation is one of the key tasks to improve the quality and efficiency of dairy cow production.At present,although feeding rumen-protected amino acids is the most direct and efficient way to improve milk protein synthesis of dairy cows,most studies only focus on a single limiting amino acid,ignoring the understanding of amino acid nutritional balance.Amino acid nutrition,as the source and signal substance of milk protein synthesis,affects the absorption and utilization of blood amino acids by cows,but its molecular mechanisms is still unclear.Therefore,this article mainly analyzed the effects and regulation of amino acids on protein synthesis in dairy cows.Firstly,it described the basic pathway of milk protein synthesis and the influence of essential amino acids,non-essential amino acids and combined essential amino acids on milk protein yield and concentration.Secondly,it introduced the impact of the supply of essential amino acids and combined essential amino acids on feed intake,blood amino acid concentration,blood flow and mammary gland cells of dairy cows,while emphasizing the optimal supplemental dose of amino acids required for mammary gland cell culture and the specific regulation of essential amino acids on amino acid transporters and signaling pathways in cellular molecular angle.In summary,through the discussion of the factors and molecular regulation mechanism of mammary gland protein synthesis,it can not only help to optimize the ideal amino acid ratio in feed and scientific production mode,but also provide theoretical reference for improving the synthesis of milk protein by amino acid nutrition in related filed.

Key words: Dairy cow, Milk protein, Amino acids, Mammary gland cells, Nutritional regulation