The absorption of milk precursors by the mammary gland

Abstract
The acid soluble P content of the jugular blood of lactating and non-lactating cows is lower than that of arterial blood; this is true of both organic and inorganic acid-soluble P. The inorganic P content of mammary blood is higher than that of jugular blood and approximately the same as that of arterial blood of both lactating and non-lactating cows. The organic acid-soluble P content of mammary venous blood is lower than that of arterial blood in lactating cows, but slightly higher in non-lactating cows.