The functional and nutraceutical food are more preferred and consumed by the health conscious people. Milk and milk products are considered as complete food containing most of the nutrients required for healthy life. The nutrients contents and its proportion in the milk can be modified by either incorporating required functional ingredients directly into fluid milk/dairy products or modifying the feed formulation of lactating animals to get desired milk composition. The modification of feed formulation not only results in secretion of milk of desired composition but also reduces the chances of incidence of certain diseases in lactating animals. Modification or enrichment in milk/milk products can be done in several ways such as modifications in protein/amino acid composition, modifications in fat/fatty acid profile, alteration in lactose, humanization of bovine milk, eliminating β-lactoglobulin from milk, milk with human therapeutic proteins, decreasing of milk allergies, melatonin enriched milk and many more types of the modified or enriched milk can easily be obtained for the specific proposes.