🥛 Milk

Milk is the liquid produced by the mammary glands of female mammals to feed their young. For newborns it is the first and, at first, the only food: milk contains water, fats, proteins (caseins and whey proteins), the milk sugar lactose, minerals and vitamins. Its composition depends heavily on the species: donkey milk has less than 1% fat, cow’s milk about 3.5–4%, seal milk tens of percent. The Codex Alimentarius defines milk as the normal mammary secretion of milking animals obtained from one or more milkings.

People began milking animals soon after domesticating them. Analysis of fat residues on ancient pottery shows that dairying existed in Southwest Asia as early as the 7th millennium BC. Later, independently and at different times, milking appeared in Africa, South Asia, the Eurasian steppes and the Arabian Peninsula.

According to the FAO, the world today produces more than 900 million tonnes of milk a year (about 930 million tonnes in 2022), and about 150 million households are involved in producing it. Roughly four-fifths of all milk comes from cows, followed by buffalo, goats, sheep and camels. The ability of adults to digest lactose is unevenly distributed: by estimates, most adults in the world lose some lactase enzyme activity with age.