Origin: Milk has been a part of our nutrition since time immemorial. During 10,000 B.C., "Agricultural revolution" took place, nomadic tribes decided to stop wandering and to settle down in farming communities. With this came domesticated animals and the origin of by-products such as milk. 
Later, in ancient Egypt, milk and other dairy products were available, but were only chartered for royalty, priests and the very wealthy. By the 5th century AD in Western Europe, milk was taken from both cows and sheep. However, by the 14th century, cows’ milk was more popular.

During the 19th century, in western Europe and the US, milk was becoming more familiar, but only for young people and fresh cows’ milk was for babies only, whilst the further it got from the cows who produced it, the more it was likely to be adulterated by bacteria. 
In 1862, Louis Pasteur, a French microbiologist, conducted the first pasteurization tests. The first milk bottle was invented in New York State in 1884.

Ultimately, it all came together in the early 20th century.  In the 1930s, milk cans were replaced with big on-farm storage tanks, and plastic-coated paper milk boxes were designed, which allowed for the extensive distribution of fresh milk. 
As per Ayurvedic pure milk is considered like plasma that nourishes all the tissues. However, poor-quality milk is considered similar to pure mucus (the waste product of the plasma). Ayurveda states that milk is pregnant with special and unique nutrition that are not present in any other type of food.  Ayurveda also states that milk nourishes tissues, promotes balanced emotions, and helps to balance all the doshas.

As per Ayurveda, milk should not be consumed with sour, bitter, salty, astringent, or pungent tastes.

Scientifically: Milk carries many molecules of a protein called casein. Each casein molecule is a monomer and a chain of casein monomers is a polymer. The polymer can be scooped up and molded, which is why plastic made from milk is called casein plastic. 
Milk contains a wide array of nutrients, including vitamins, minerals, protein, healthy fats and antioxidants. Conjugated linoleic acid and omega-3 fatty acids present in milk are linked to many health benefits, including a reduced risk of diabetes and heart disease. Organic and grass-fed cow’s milk contains higher amounts of beneficial antioxidants, such as vitamin E and beta-carotene, which help in reducing inflammation and fight oxidative stress.
Milk is a rich source of quality protein which carries all nine essential amino acids. It may reduce age-related muscle loss and promote muscle repair after exercise. Milk contains a variety of nutrients such as calcium, vitamin D, phosphorus and magnesium that benefit bone health. 
Many studies suggest that consuming milk and dairy products might prevent osteoporosis and reduce the risk of fractures. Adding whole milk to your diet may prevent weight gain. 

Raw milk is blessed with B-vitamins, alpha hydroxy acids, calcium, and other potent antioxidants. Thus it works as a wonderful skin moisturizer, exfoliator and also cures acne. 

The vitamin A in milk addresses dry, flaky and peeling skin. Milk’s Vitamin D ensures you have youthful glowing skin as it boosts collagen production. Vitamin B6 in milk leads to new skin cell formation.  Biotin is milk addresses dry, withered skin. The protein in milk repairs tissues and fights wrinkle. Vitamin B12 in milk restores uneven skin and is blessed with skin-lightening properties.  The Lactic Acid in milk moisturizes, hydrates and nourishes dry skin.  The Potassium in milk caters to dry, itchy skin. Milk’s Magnesium takes care of the aging process.  

Usage: Milk is a nutritious beverage that is consumed all across the globe. Apart from drinking, milk is used in various dishes, desserts, and drinks. Smoothies, shakes, coffee, tea, soup, cake are a few of these. Many dairy products including yogurt, different kind of cheese, butter, etc are made from milk to be used in different food items. Milk is also used in many beauty products to get a soft and glowing skin and hair. It is used as a natural cleanser, makeup remover, etc.  

Below are some DIYs with for beautiful hair and skin:

-     To mashed ripe avocado add 1 tablespoon of milk. Apply this beautiful mixture on your face. Leave it for 15 minutes and then wash off to discover smooth skin. 
-    Take a teaspoon of lemon juice and 2 teaspoons of raw milk. Mix well and apply with a cotton ball. Rinse after 15 minutes. This remedy works as an excellent facial toner.
-    Take a teaspoon of gram flour, and add a teaspoon of milk to it. Apply this paste on the face and let it dry for 10 minutes and then rinse. This mask helps in deep cleansing and moisturizing of the skin.
-    Soak 5-6 almonds and 5-6 dates in raw milk for about an hour. Then grind all the three ingredients together to get a paste. Leave this paste on the face for 15-20 minutes. Rinse later. This mask helps in removing tan. 
-    Take a pinch of turmeric, half teaspoon of saffron and a teaspoon of milk. Apply this to your face and let it dry for 2-3 minutes. Gently rub and rinse it off. This mask adds radiance to the skin.