Mutual relationship between milk components and lysosome enzymatic activity in abnormal milk.

Abstract

The present investigation was carried out with 67 quarter milk of lactating cows in the field to verify the relationship among the lysosome activities, the cell count and the milk components. Of lysosome enzymes, N-acetyl-β-D-glucosaminidase (NAGase), β-glucuronidase and acid phosphatase exhibited high correlation with the cell count. When the cell count was expressed in logalithm, NAGase showed a correlation coefficient ranging from 0.679 to 0.769 and β-glucuronidase from 0.592 to 0.720. Acid phosphatase showed, however, a decrease in the coefficient from 0.680 to 0.432. NAGase showed a considerably high correlation with β-glucuronidase, acid phosphatase and arylsulphatase with r=0.672∼0.675. Aldorase exhibited a high correlation with NAGase with r=0.687 and with acid phosphatase with r=0.682, but not so high a correlation with β-glucuronidase. Chloride exhibited a remarkably high correlation with NAGase (r=0.875) and arylsulphatase (r=0.767) and a low correlation with β-glucuronidase. When examined for correlation with enzymatic activities, lactose correlated to NAGase with r= -0.810, to acid phosphatase with r= -0.676, to arylsulphatase with r=-0.687, and to aldorase with r=-0.612. When examined for correlation with each enzymatic activity, milk protein showed a considerably high correlation with β-glucuronidase and α-mannosidase. Milk fat exhibited a correlation with β-glucuronidase, α-mannosidase and arylsulphatase (r=0.453∼0.567). From these results it was concluded that of the lysosome enzymes, NAGase could be used as an indicator of inflammation in the udder and that β-glucuronidase might be utilizable for diagnosis of mastitis.