Functional roles of amino acids in regulation of milk fat and protein synthesis

由于计算机模型的改进，可以根据奶牛对其饮食的描述来预测氨基酸的吸收率，因此，除了满足作为蛋白质构建块的需求之外，利用氨基酸营养的功能方面有了新的机会。对其他动物的研究表明，氨基酸对生理和代谢有一系列不同的影响，因此，氨基酸同样可以影响奶牛乳腺中的信号传导和基因表达，这不是不合理的。我们的目标是在培养的乳腺细胞（目标1）、泌乳大鼠（目标2）和奶牛（目标3）的乳腺组织中描述特定氨基酸在蛋白质和脂肪合成方面的功能和分子反应。然后将描述乳成分对氨基酸响应的方程纳入工业合作伙伴的日粮评估模型，该模型将用于制定膳食氨基酸谱，以实现所需的乳成分响应（目标4）。修订后的模型和从该项目中获得的知识将被Nutreco Canada Inc.用于优化客户牛群奶牛的泌乳性能，并提高加拿大牛奶生产的可持续性和安全性。本项目拟招聘博士后1名、研究生1名、本科生2名。

Due to improvements in computer models that predict rates of absorption of amino acids by dairy cows based on a description of their diet, there are new opportunities to exploit the functional aspects of amino acid nutrition, outside the scope of meeting requirements as building blocks of proteins. Studies in other animals have shown that amino acids exert a range of diverse influences on physiology and metabolism and it is not unreasonable to expect that amino acids can similarly affect signalling and gene expression in the mammary glands of dairy cows. Our objectives are to characterize the functional and molecular responses to specific amino acids in terms of protein and fat synthesis in mammary cells in culture (objective 1), in mammary tissue of lactating rats (objective 2) and cows (objective 3), and then to incorporate equations describing milk composition responses to amino acids into the industrial partner's ration evaluation model that will be used to formulate dietary amino acid profiles to achieve a desired milk component response (objective 4). The revised model and knowledge gained from the project will be used by Nutreco Canada Inc. to optimize lactational performance of cows in client herds and improve the sustainability and security of milk production in Canada. The project will employ ½ postdoctoral fellow, a graduate student, and 2 undergraduate students.