Effects of β-glucan extracted from Saccharomyces cerevisiae on growth performance, and immunological and somatotropic responses of pigs challenged with Escherichia coli lipopolysaccharide1

Three experiments were conducted to investigate the effects of β-glucan supplementation on pig performance and immune function. In Exp. 1, 100 weaned pigs (8.65 ± 0.42 kg of BW and 28 ± 2 d of age) were used in a 35-d experiment to determine the effects of graded levels of β-glucan. Pigs were randomly allotted to 1 of 5 treatments containing β-glucan supplemented at 0, 25, 50, 100, or 200 ppm. Each treatment was replicated using 5 pens containing 4 pigs per pen. The ADG of pigs between d 14 to 28 and d 0 to 28 responded to dietary β-glucan in a quadratic fashion (P < 0.05), whereas β-glucan had no effect on ADFI and G:F in any period. In Exp. 2, 80 crossbred pigs (8.23 ± 0.56 kg of BW and 28 ± 2 d of age) were used in a 35-d experiment. Pigs were allotted to 1 of 2 dietary treatments (0 or 50 ppm of β-glucan in the diet) using 10 pens with 4 pigs per pen. Pigs treated with β-glucan had greater ADG in the 14to 28-d (P = 0.05) and 0to 28-d (P = 0.035) periods. The ADFI of pigs receiving β-glucan was increased (P < 0.05) in the periods from 0 to 14, 0 to 28, and 28 to 35 d. The lymphocyte proliferation index in response to phytohemagglutinin (P = 0.051) and concanavalin A (P = 0.052) tended to de