COMPARISON OF MINERALS IN MILK OF 4 SPECIES

1. Milk samples of 4 ml or more were obtained from guinea pigs (Cavia porcellus), dairy cattle (Bos taurus), horses (Equus caballus) and humans (Homo sapiens). The milks were analysed for minerals including calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K) and sodium (Na) by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). 2. Calcium was approximately twice as concentrated in guinea pig milk as in cows' milk, which was twice as much as the level in mares' milk, and this, in turn, was twice as concentrated as human milk. 3. The ratio of Ca to P in guinea pig milk was 1.66:1, while it was 1.24:1 in cows' milk, 1.56:1 in mares' milk and 2.07:1 in human milk. 4. Potassium was the most abundant mineral in the milks of cows, mares and humans, but not in guinea pig milk, and was much higher in cows' milk than in others. 5. Sodium was highest in guinea pig milk with cows' milk being a close second.(~)6. Magnesium was one-tenth as concentrated as Ca.