Abstract
1) The sialic acid content in casein measured with SVENNERHOLM'S resin method gave slightly higher value than WARREN'S thiobarbituric acid method.
2) SVENNERHOLM'S resin method was preferably convenient to determine the sialic acid in skim milk, and the sialic acid content in whole casein was measured easily with WARREN'S thiobarbituric acid method.
3) The sialic acid content in individual milks varied from 0.40 to 0.59% and that in colostrum immidiately after calving showed remarkably high values.
