Effect of β-glucans on an ETEC infection in piglets.

Abstract The effect of orally administered β-glucans in protecting pigs against an ETEC infection after weaning was analysed in this study. Three β-glucans that differed in origin ( Saccharomyces cerevisiae (MCG (Macrogard) and G2) or Sclerotium rolfsii (G3)) and/or extraction procedure were tested. Pigs fed for 2 weeks after weaning with these glucans were less susceptible to an F4 + ETEC infection in comparison with the control group. This was evidenced by a reduction in the faecal excretion of F4 + Escherichia coli as well as a reduced F4-specific serum antibody response. This decrease in faecal excretion was statistically significant for pigs fed with the MCG glucan in a first experiment and with the G3 glucan in a second experiment; diarrhoea was milder in the glucan-supplemented groups and was significantly reduced in the MCG-supplemented group. Furthermore, a lower amount of F4-specific IgM antibody-secreting cells (ASC) was found in the lymphoid tissues of pigs fed with G2 or G3 glucans in comparison with the control pig, as well as lower F4-specific IgA ASC in G3-fed pigs in comparison with the control pig. This study showed that β-glucans can protect against an ETEC infection. Both MCG from S. cerevisiae and G3 from S. rolfsii , resulted in significant effects. To our knowledge, this is the first in vivo study, in which the use of β-glucans as feed ingredient for just-weaned piglets was tested for their protective effects against ETEC infection.