Mature milk is thinner (not thicker) with all essential nutrients for growth. Colostrum In initial 3 to 4 days Small quantity, thick, and yellow in color Large amount of antibodies, immune component cells; and vitamin A,D,E and K Transitional milk: Secreted after 3 to 4 days until 2 weeks Immunoglobulin and protein content decreases, while the fat and sugar content increases. Mature Milk: Follows transitional milk Thinner and more watery Contains all the nutrients essential for optimal growth of the baby Foremilk: Secreted at the sta of the feed Watery and rich in proteins, sugar, vitamins, minerals, and water that quenches the baby&;s thirst Hind milk: Comes towards the end of the feed Provides more energy and sense of satiety and it is richer in fat. Preterm milk: Milk of mother who delivers before 37 weeks Contains more proteins, sodium, iron, immunoglobulins, and calories as per requirement of the preterm infant. Ref : Ghai Essential pediatrics 9th edition Pgno: 147