Lactating in the context of "Mother"

Milk is a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digest solid food. Milk contains many nutrients, including calcium and protein, as well as lactose and saturated fat; the enzyme lactase is needed to break down lactose. Immune factors and immune-modulating components in milk contribute to milk immunity. The first milk, which is called colostrum, contains antibodies and immune-modulating components that strengthen the immune system against many diseases.

As an agricultural product, milk is collected from farm animals, mostly cattle, on a dairy. It is used by humans as a drink and as the base ingredient for dairy products. The US CDC recommends that children over the age of 12 months (the minimum age to stop giving breast milk or formula) should have two servings of milk products a day, and more than six billion people worldwide consume milk and milk products. The ability for adult humans to digest milk relies on lactase persistence, so lactose intolerant individuals have trouble digesting lactose.

The nipple is a raised region of tissue on the surface of the breast from which, in lactating females, milk from the mammary gland leaves the body through the lactiferous ducts to nurse an infant. The milk can flow through the nipple passively, or it can be ejected by smooth muscle contractions that occur along with the ductal system. The nipple is surrounded by the areola, which is often a darker colour than the surrounding skin.

Male mammals also have nipples but without the same level of function or prominence. A nipple is often called a teat when referring to non-humans. "Nipple" or "teat" can also be used to describe the flexible mouthpiece of a baby bottle.