Milk

Milk is a usually white liquid food, but it can also be shades of yellow, cream, pink, or brown. It is produced by the mammary glands of lactating mammals and is the primary source of nutrition for young mammals before they can digest solid food. Milk contains important nutrients like calcium and protein, as well as lactose and saturated fat. To digest lactose, the body needs an enzyme called lactase.

As an agricultural product, milk is collected from farm animals, mostly cattle. It is used by humans as a drink and as the base for many dairy products. Health organizations recommend that children over 12 months old include milk products in their diet each day. Many people around the world enjoy milk and its products, and milk production is an important part of farming in many countries.

In 2011, dairy farms produced around 730 million tonnes of milk from 260 million dairy cows. India is the largest producer of milk and the leading exporter of skimmed milk powder. Other major exporters of milk products include New Zealand, Germany, and the Netherlands. Millions of people live in households that depend on dairy farming.

Etymology and terminology

The word milk comes from old English words like meoluc and milc. Many languages have similar words for milk, showing that this idea is shared across cultures.

Since 1961, rules set by Codex Alimentarius define milk as the natural liquid from animals that comes from milking, with nothing added or taken away, meant for drinking or making other products. The word dairy means places or processes where milk from animals is produced and handled.

Types of consumption

Milk is consumed in two main ways. First, all infant mammals drink milk directly from their mothers. This milk, especially the early milk called colostrum, gives babies important nutrients and protection. The World Health Organization suggests babies be breastfed exclusively for six months and continue with breastfeeding along with other foods up to two years or more.

Second, humans also drink milk from other animals, like cows, goats, and sheep, throughout their lives. This practice began thousands of years ago when a genetic change allowed some people to continue making the enzyme lactase into adulthood. Lactase helps our bodies digest lactose, the sugar found in milk. Today, milk is made into many products such as cheese, yogurt, butter, and ice cream. Different animals like yaks, water buffalo, horses, reindeer, and camels are also sources of milk in various cultures.

History

Humans began drinking the milk of other animals after they started domesticating them during the Neolithic Revolution or the rise of farming. This happened in different places around the world from as early as 9000–7000 BC in Mesopotamia to 3500–3000 BC in the Americas. The most important animals for milk were cattle, sheep, and goats, first kept in Southwest Asia. At first, these animals were raised for meat, and dairy farming developed later.

As farming spread, so did the use of milk. It moved from Southwest Asia to Europe, South Asia, and Africa. In Europe, milk became important, and some groups relied mostly on animals for food. In places like East Asia, the Americas, and Australia, milk was not commonly eaten until much later, mainly after European influence.

During the Middle Ages, milk was valued and called the "virtuous white liquor" because water was often unsafe to drink. In more recent times, improvements in transportation and technology changed how milk was produced and delivered, making it more available to many people.