Nutrition entails the sum of processes involved in the ingestion of foods, digestion, absorption, transport of nutrients, intermediary metabolism, underlying anabolism and catabolism, and excretion of unabsorbed nutrients and metabolites. Research at the Animal Nutrition Laboratory is concerned with the identification of nutritional characteristics in several animal species with the aid of comparative biochemistry and molecular biology. This mini-review provides an overview of the nutritional regulation of metabolism, physiological functions and gene expression in avian species