Intestinal Permeability to Proteins in the Newborn Herbivore

¹ From the Departments of Physiological Chemistry and Dairy Husbandry, University of Wisconsin, Madison, Wisconsin

The permeability of the gut of the newborn herbivore to the protein molecules of milk whey is largely lost within 24 hours following birth. All of the colostrum whey proteins, not only the antibody fraction, are absorbed during this stage of intestinal permeability. The nonantibody proteins are molecules of relatively low molecular weight. These are rapidly lost through the kidney, the antibodies being largely retained. Crystalline ß-lactoglobulin may be prepared from urine during the proteinuric stage which is very pronounced during the first 24 hours of postpartum life in calves that have had ready access to milk. Unsuccessful attempts were made to maintain the intestinal permeability beyond the first 24 hours of postpartum life. Hormonal and milk factors did not appear to be responsible for the discussed change. Transfusing with the blood of the mother and other biological agents were also ineffective.