A deeper understanding of human physiology depends on optimal understanding of comparative interspecies physiology. Animal physiology can be more effectively perceived via incomparable insights into greatly integrative ruminant physiology and rumen microbial physiology. [1][2][3] Ruminants are matchless food resources that should be benefited from as appropriate working pattern models for studying human medicine and health at various gene, cell, organ and individual entire body levels. 4,5 For example, night-time vs. daytime feeding of dairy cows has increased eating rate and postprandial release of intermediary metabolites from both rumen and post-rumen as well as splanchnic and peripheral tissues. 6,7 Nocturnal eating has also increased milk production of especially fat and energy. 8 Night eating, in addition, improved nutrient digestibility and efficiency in dairy and beef cattle. 5 The discoveries of such kind underline the feasibility and importance of timing of eating and exercise as a strategy to better orchestrate nutrient metabolism and partitioning in human. [9][10][11] However, it must be noted that livestock are different from human in the extent and rate of splanchnic, hepatic and mammary metabolism. It is expected that modulating eating time would have likely different impacts on ruminant vs. human nutriphyiogenomics and endocrinology. This requires future concentration on interdisciplinary and interspecies nutritional and metabolism experiments.