Sialoglycoconjugate content of milk replacers for neonatal calves

Abstract

Sialoglycoconjugate contents of several milk replacers (MR) currently used in Spain have been determined. The ingestion of these compounds by calves fed bovine milk or MR is also discussed. Total sialic acids and glycoprotein-, oligosaccharide-, casein-, and lipid-bound sialic acids and free sialic acid were determined. High sialic acid contents in all the fractions studied, including total sialic acids, were found. N-acetylneuraminic acid was found to be the major sialic acid in MR. However, MR-D and H had a high N-glycolylneuraminic acid (NeuGc) content in all fractions (15-40%), while E and F only had a high NeuGc content in the glycoprotein fraction. Five different sialyloligosaccharides -3'-sialyllactose, 6'-sialyllactose, 3'-sialyllactosamine, 6'-sialyllactosamine, and disialyllactose, which are the most abundant oligosaccharides in bovine milk-were detected in the MR. Samples B to I contained high amounts of these oligosaccharides. The content of individual gangliosides was very similar to that of bovine milk, with GD3 as the major ganglioside. Although MR are not formulated as regards their sialic acid content, high amounts of sialic acid-containing glycoconjugates with high levels of NeuGc, a sialic acid critical in the adhesion of some Escherichia coli strains to calf intestinal epithelium were detected. The ingestion of MR analyzed in this work could protect newborn calves from several enteric pathogens.Additional key words: gangliosides, milk oligosaccharides, sialic acids. ResumenContenido de sialoglicoconjugados de algunos lactorreemplazantes usados en la alimentación de terneros recién nacidos

Molecular cloning, sequence characterization, and tissue expression analysis of three water buffalo (<i>Bubalus bubalis</i>) genes – <i>ST6GAL1</i>, <i>ST8SIA4</i>, and <i>SLC35C1</i>

“…Glycoconjugates are some of the most important bioactive components in milk, but little or no attention has been paid to these minor components in milk (Martín-Sosa et al, 2009). Previous studies have shown that ST6GAL1, ST8SIA4, and SLC35C1 genes play important roles in the synthesis of glycoconjugates (Hamamoto and Tsuji, 2002;Hellbusch, 2007;Yang et al, 2012).…”

“…They protect against pathogens by acting not only as competitive inhibitors through binding on the epithelial surface of the intestine but also as growth promoters for colonic bacterial flora (Newburg, 1999;Gopal and Gill, 2000;Nakano et al, 2001). A number of studies on major components of milk have been performed; however, less attention has been paid to minor components in milk such as glycoconjugates (Martín-Sosa et al, 2009).…”