The results were consistent with the clinical signs and showed that in non-challenged pigs, MOS increased the expression of genes for cell receptors and those involved in immunity. However, in the PRRSV-infected pigs, MOS reduced the expression of cytokine and chemokine genes involved in inflammatory responses. This combination of responses explains the enhanced immune response and the reduction of fever, Che said.
"MOS stimulates the immune system and enhances the immune response, except when the immune system is already challenged," Pettigrew explained. "MOS actually reduces the inflammatory response in pigs with challenged immune systems. This may be how the product improves growth performance because it redirects nutrients to growth rather than the immune system."
Che said MOS also improves feed efficiency from Day 7 to 14 after inoculation with PRRSV.
"PRRSV interferes with the immune response and makes pigs more susceptible to bacterial infections," Pettigrew said. "This product seems to counteract this effect. It may even reduce bacterial infections associated with PRRSV, although we did not test that specifically."
This team of researchers is also repeating this experiment with a second generation of MOS-like products to learn more about how this mechanism in MOS works.
"We are increasingly concerned about the importance of keeping pigs healthy, so we direct much of our research program to looking at things we can do in the diet to improve the health of pigs," Pettigrew said.
"Mannan oligosaccharide modulates gene expression profile in pigs experime
|Contact: Jennifer Shike|
University of Illinois College of Agricultural, Consumer and Environmental Sciences