Bovine milk contains 2%–5% lipids, secreted by breast epithelial cells and dispersed in the milk in the form of milk fat globules. Most of the milk fat (about 98%) exists in the milk fat globules in the form of glycerolipids, and the rest (about 2%) is polar lipids, including glycerophospholipids, sphingolipids, glycolipids, mainly distributed in the milk fat globule membrane surface. Despite their relative scarcity, milk polar lipids play an indispensable role in the growth and development of mammals. This review introduces readers to the types of polar lipids in milk, and compares the types and quantities of milk polar lipids from different milk sources including cows, buffalo, yak, sheep, goats, donkeys, camels, and humans. Next, this review summarizes the physiological functions of milk polar lipids including inhibition of neutral fat absorption, regulation of intestinal microbial community composition, prevention of cardiovascular disease, prevention of non-alcoholic fatty liver, promotion of cognitive function and nervous system development, and anti-inflammatory effects with a view to providing reference for the research and development of functional milk fat products.

China is blessed with minor species milk resources. Minor species milks from different sources have their own distinctive characteristics in terms of nutrient composition and content as well as functional activity. Oligosaccharides, as important bioactive ingredients in milk, have many significant biological functions. With the aim of providing theoretical reference for the development and utilization of oligosaccharides in minor species milk, this paper reviews recent progress in the research on the types, structures and contents of oligosaccharides in goat milk, donkey milk, buffalo milk, camel milk and horse milk, and it also summarizes the bioactive functions of milk oligosaccharides such as probiotic, antibacterial and anti-inflammatory properties as well as promoting brain development.