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

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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.****