| Issue |
Lait
Volume 42, Number 413-414, 1962
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|---|---|---|
| Page(s) | 152 - 159 | |
| DOI | https://doi.org/10.1051/lait:1962413-4147 | |
DOI: 10.1051/lait:1962413-4147
Les variations de la composition minérale du lait de vache
L. GUEGUEN, M. JOURNET and Michelle LANGLOISService de Biochimie et de Nutrition et Station de Recherches sur l'Elevage, Centre national de Recherches zootechniques, Jouy-en-Josas (S.-et-O.)
(Reçu en décembre 1960.)
Abstract - Variations in mineral composition of cow's milk
The study of variations in the P, Ca, K, Na and Mg contents of milk in the course of lactation has been carried out with 10 cows of 3 different breeds which had all calved at the beginning of the winter and which had all received the same diet. The determinations were carried out on a weekly sample obtained from all the milkings of the week using the vanadate colorimetric method for P, and flame spectrophotometry for Ca, K, Na and Mg after nitro-perchloric digestion.
In the course of lactation, the K content diminishes regularly whereas the Na content increases, especially at the end of lactation. The Ca and P contents are highest at the beginning and end of lactation.
The milk from Normandy cows appears to be richer in Ca and poorer in K than the milk from Fresian and Eastern Red Pied cows.
The mineral composition of the milk is not affected if the animals are put out to pasture