Phone: (519) 824-4120 ext. 56222
Office: ANNU 239
John supervises a dynamic group of students who use a combination of in vivo, in vitro, and in silico techniques to study the physiological and biochemical regulation of milk synthesis in dairy cows, and the metabolic consequences of cows’ milk consumption in animals. John teaches animal metabolism and conducts research with a systems biology approach where whole-animal function is explained as a consequence of biochemical activities in individual cells. His lab makes measurements of milk protein, fat and lactose synthesis in mammary cells, or cell-free preparations, or in the udders of cows infused intra-arterially, intravenously or abomasally with nutrients to develop hypotheses that explain effects of the cow’s diet and physiological state on milk yield and composition. These hypotheses are expressed in mathematical form in computer simulation models that can be used to predict how much milk a cow will produce and what the nutritional quality will be. A particular interest is regulation of translation of the milk protein mRNAs by characteristics of the mRNA sequences and by activity state of initiation and elongation factors in the mammary glands. Combining these features with descriptions of milk secretory cell turnover and local control of mammary blood flow provides a systems view of milk synthesis. The lab also studies health implications for humans of consuming milk components in the diet, particularly in relation to insulin sensitivity.