a1 Department of Biochemistry, University of Western Australia, Nedlands, Western Australia 6009, Australia
a2 1Department of Obstetrics and Gynaecology, University of Western Australia, Nedlands, Western Australia 6009, Australia
1. The intake of mammary secretion from delivery to day 5 post-partum was determined by test-weighing nine infants using an integrating electronic balance. The mean yield of colostrum for the first 24 h after birth was 37.1 (range 7.0–122.5) g and was 408 (range 98.3–775) and 705.4(range 452.5–876)g/24h on days 3 and 5 post-partum respectively.
2. The milk yield of mothers on either day 14 or 28 post-partum was determined by test-weighing the mother. The mean milk yield was 1.156 (SD 0.167) kg/24 h.
3. A significant correlation (P < 0.001; r 0.85, n 42) was found between milk yield measured by test-weighing the infant and milk yield measured by test-weighing the mother, confirming that it is possible to obtain a similar estimate of milk consumed using either of the two methods of test-weighing
4. There was a significant positive correlation (P < 0.001) between lactose concentration and milk yield for the first 5 d post-partum (r 0.76, n 22); a significant negative correlation (P < 0.001) between protein concentration and milk yield (r – 0.74, n 22) and no significant correlation between fat concentration and milk yield for the period studied.
5. The calculated energy intake of infants during the first 24 h after birth was only 0.12 (range 0.02–0.29) mJ. This increased to 1.44 (range 0.83–2.18) and 2.99 (range 2.49–4.06) mJ/24 h by days 3 and 14–28 post-partum respectively.
(Received August 23 1983)
(Accepted February 17 1984)