Some constituents of human colostrum, transitional, and mature milk and of cow's milk

(average values per 100 millilitres whole milk)

colostrum

(1–5 days) transitional

(6–14 days) mature (after

14 days) cow's milk

energy, kcal* 58 74 71 69

total solids, g 12.8 13.6 12.4 12.7

fat, g 2.9 3.6 3.8 3.7

lactose, g 5.3 6.6 7.0 4.8

protein, g 2.7 1.6 1.2 3.3

casein, g 1.2 0.7 0.4 2.8

ash, g 0.33 0.24 0.21 0.72

Minerals

calcium, mg 31 34 33 125

magnesium, mg 4 4 4 12

potassium, mg 74 64 55 138

sodium, mg 48 29 15 58

iron, mg 0.09 0.04 0.15 0.10

*Kilocalorie; sufficient energy to raise the temperature of 1 kilogram of water 1 degree Centigrade.