LACTATIONAL CHANGES IN THE N-GLYCOLOYLNEURAMINIC ACID CONTENT OF BOVINE-MILK GANGLIOSIDES

The N-glycoloylneuraminic acid (Neu5Gc) contents of milk and milk gang liosides from bovines were investigated during the different stages of lactation. The Neu5Gc content of milk is high in the colostrum (32% o f the total sialic acid content of milk) and decreases thereafter unti l the end of the period considered (6% on day 30). When the Neu5Gc con tent of gangliosides was evaluated a similar profile to that of Neu5Gc in total sialic acids was found. Gangliosides from colostrum showed t he highest Neu5Gc content (21-22% of the total sialic acid content of milk gangliosides). This content dropped towards the end of the period studied (8 % on day 90). Our results indicate that a significant supp ly of Neu5Gc by the milk could be important for the newborn during the first days after parturition.