Effects of β-glucan extracted from S. cerevisiae on growth performance,
and immunological and somatotropic responses
J Li, DF Li, JJ Xing, ZB Cheng, CH Lai.2006. Journal of Animal Science 84: 2374-2381
13-Sep-2007 (18 years 8 months 25 days ago)Beta-glucans extracted from cell walls of yeast are referred as stimulators of
the immune system. The aim of the study was to evaluate the effects of dietary
supplementation of β-glucan on performance, evaluating the immunological and somatotropic
response in challenged pigs with E. coli lipopolysaccharide.
Three experiments with weaning pigs were conducted. In the first the effects of graded levels of dietary β-glucans (0, 25, 50, 100, 200 ppm) on pig performance were studied in a 5 week experiment. Results obtained showed that the average daily gain responded in a quadratic way, the highest ADG from 0 to 28 days being found for 50 ppm fed group.
The second trial was carried out with two experimental diets, a control diet and
a diet containing 50 ppm of β-glucans. Eighty weaned piglets were distributed
into 20 pens and the experimental period lasted for 5 weeks. Performance was monitored
throughout the experimental period and on day 14 and 28 blood samples from the
animals were obtained for assessment of the lymphocyte proliferation index. As
in the first experiment β-glucan supplementation resulted in an increase of
ADG (P= 0.035). Lymphocyte proliferation in response to phytohemaglutinin and
concanavalin was higher on day 14 in piglets fed β-glucans, while no response
was found on day 28.
Finally the third experiment was carried out to determine the influence of β-glucan
on the immune and somatotropic responses of weaned piglets when challenged with
LPS from E.coli. Results showed that dietary β-glucan (50 ppm) reduced,
compared to the control diet, the increase provoked by LPS in the plasmatic IL-6
and TNF-alpha concentration, the proinflammatory cytokines that modulate immunity
and regulates nutrient metabolism. Moreover, β-glucan supplementation determined
an increase, in LPS challenged piglets and compared to the control diet, in the
concentration of IL-10 an anti-inflammatory cytokine.
Thus, feeding β-glucans to the weaning pig may result in a lowered activation
of the immune system during the feeding period resulting in an increased growth
performance.