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.
J Li, DF Li, JJ Xing, ZB Cheng, CH Lai.2006. Journal of Animal Science 84: 2374-2381