Abstract
Fractionation of bovine milk protein by zone electrophoresis has been performed during first 7 days after parturition.
Whey roteins of colostrum were fractionated using cellulose acetate membrane in a veronal buffer. Immediately after parturition the total protein content of bovine colostrum was high and the major proteins were immunoglobulins, especially euglobulin. The ratio of euglobulin to total whey protein was 65%. Euglobulin content fell very rapidly and was soon less than pseudoglobulin.
Caseins of colostrum were fractionated by means of polyacrylamide gel electrophoresis in a Tris-EDTA-boric buffer containing 7 M urea. The electrophoretical patterns of colostrum were similar to normal milk but the κ-casein content of the colostrum between the first day and the forth day were high. The casein derived from colostrum obtained immediately after parturition contained 0.88% sialic acid.
