Variations in the Electrophoretic Distribution of Low Density Lipoproteins of Holstein Cows

The properties of serum lipoproteins during various stages of gestation and lactation of Holstein cows are being characterized. This paper reports changes in the electrophoretic distribution of serum low density lipoproteins. Electrophoretie a-lipoproteins normally can be isolated ultracentrifugally in the high density lipoprotein class of most mammals, but in certain eases a-lipoproteins have been isolated in the low density lipoprotein class as well. Low density a-lipoproteins of Holstein cows have been observed to increase during lactation. The possible relationship between these a-lipoproteins and very low density lipoprotein metabohsm i.~. discussed.