[Experimental data on milk casein absorption into the blood in the early postnatal period of development]

Blood absorption of unchanged molecules of the food protein casein was studied. Of 18 test serum samples withdrawn from portal blood of a satiated lamb, only 8 contained casein-like protein that had an immunoelectrophoretic mobility of casein and provided a reaction identical to that of casein preparation. Casein hydrolysis products did not interact with anticasein serum. The evidence obtained warrants the conclusion that under normal physiological conditions an insignificant part of casein may be absorbed unchanged by blood from the intestinal lumen during the early postnatal development.