ABSTRACT
The lactating mammary gland synthesizes and secretes nutrients into milk very efficiently. For example, milk yield can range from 49 ml/d in the rat up to 38 1/d in the cow. 1 , 2 Consideration of protein concentration in milk shows the rat to secrete 8 g of protein per day and the cow secretes an average of 1300 g/d. 1 , 3 This tremendous secretory capacity drives the mammary gland to effectively compete for dietary nutrients.
