Changes in pig digesta mucin and glycoprotein content at weaning and with the inclusion of galactose in the postweaning diet were studied, Mucus was collected from ileal contents of cannulated pigs pre- and postweaning, and glycoproteins were analysed based on staining patterns and size exclusion chromatography, An increased concentration of intestinal mucin in lumen contents was observed in newly weaned pigs compared to the same pigs prior to weaning. Analysis of O-linked oligosaccharides indicated changes in mucin structure from pre- to postweaning, Supplementing the diet with galactose resulted in modification of mucin in postweaned pigs compared to a control diet and may Limit microbial degradation of mucin, These data indicate that weaning and the subsequent transition to a grain-based diet result in changes to digesta mucin and endogenous glycoproteins; and dietary galactose may play a role in the final composition and quantity of these compounds. (C) 2000 Society of Chemical Industry.