During the first two or three days after delivery, thick and yellowish fluid is secreted from the mammary gland. This differs from the regular milk and is called colostrum. It is secreted in small quantity of about 10 to 40 ml.
- It is rich in protein.
- The total fat content of colostrum is less than mature milk.
- It has more amount of vitamin a and k.
- The concentration of lactose is also less.
- The levels of niacin, pantothenic acid, biotin and riboflavin are also low.
- Vitamin c is secreted at about the same level as in mature milk.
- Zinc content of colostrum is 20 mg/dl.
- Where as mature milk has 2.6 mg/dl.
The composition of colostrum is:
- Energy: 58 kcal
- Fat: 2.9 gm
- Calcium: 31 mg
- Phosphorus: 14 mg
- Iron: 0.09 mg
- Protein: 2.7 gm
- Lactose: 5.3 gm
- Carotene: 186 i. U.
- Vitamin: 296 a. I. U.