The composition and functions of milk are as follows:

Protein

Milk contains about 3.5% protein (human milk is about 1.25%), and is mainly casein, followed by For lactalbumin and lactoglobulin. They all contain all essential amino acids, their relative content is similar to that of egg protein, and their digestibility is high, 96.1. Casein accounts for about 86% of the total protein, lactalbumin accounts for about 9% of the total protein, lactoglobulin accounts for about 3% of the total protein, and others include serum albumin, immunoglobulins and enzymes.

Fat

Milk contains fat 3.4-3.8 (human milk contains about 3.7). It is in the form of fine fat particles (diameter 2-5μm) highly dispersed in milk, so it is easy to digest. Absorbed, its digestibility reaches 97. The composition of fat is mainly saturated palmitic acid and stearic acid, accounting for about 40%, saturated short-chain fatty acids such as butyric acid and caproic acid accounting for about 9.0%, unsaturated oleic acid accounting for 30%, linoleic acid and linolenic acid only accounting for 3.0, and the rest are lauric acid and myristic acid.

Carbohydrates

The carbohydrates in milk are mainly lactose, whose content is 4.6-4.7, which is less than the lactose in human milk (content 7.0-7.86). Milk is used to feed babies When using it, you can use an appropriate amount of dilution and add appropriate sucrose to ensure sufficient heat energy, sweetness and protein comparable to human milk. Lactose can regulate gastric acid, promote gastrointestinal motility and digestive gland secretion, promote the reproduction of certain lactic acid bacteria in the intestine, and inhibit the growth of putrefactive bacteria.

Vitamins

The vitamin content in milk is related to the cow’s feed. In summer, cows eat more grass, and the vitamin A content in milk is also higher. In summer, the sunshine is longer and the content of vitamin D is higher. Each 100g of milk contains 160 μg of riboflavin and 45 μg of thiamine. Milk does not contain much vitamin C and vitamin D, so babies who feed on milk should pay attention to supplementing vitamin C and vitamin D or fortifying milk.

Inorganic salts

Milk contains 0.7-75 inorganic salts, goat milk is 0.9, and is particularly rich in calcium, phosphorus, and potassium. 1L of milk can provide 1g of calcium, and the ratio of calcium to phosphorus in milk is 1.2:1, which is close to human milk (human milk is 1:1). The digestion and absorption rate is high, so it can ensure the baby's need for calcium. There is very little iron in milk, only 0.2mg/100g, which is 1/5 of human milk. If babies are fed milk as the main food, they need to add foods containing iron and vitamin C in time, such as egg yolks, pig liver puree, green vegetable puree, etc. In addition, milk also contains copper, zinc, manganese, and iodine