title: Effects of beta-glucan extracted from Saccharomyces cerevisiae on growth performance, and immunological and somatotropic responses of pigs challenged with Escherichia coli lipopolysaccharide.
abstract: Three experiments were conducted to investigate the effects of beta-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 beta-glucan. Pigs were randomly allotted to 1 of 5 treatments containing beta-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 beta-glucan in a quadratic fashion (P < 0.05), whereas beta-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 beta-glucan in the diet) using 10 pens with 4 pigs per pen. Pigs treated with beta-glucan had greater ADG in the 14- to 28-d (P = 0.05) and 0-to 28-d (P = 0.035) periods. The ADFI of pigs receiving beta-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 decrease on d 14 in pigs supplemented with beta-glucan compared with pigs without supplementation. In Exp. 3, 24 barrows (8.89 +/- 0.20 kg of BW and 28 d of age) were used to investigate the immunological and somatotropic responses of pigs challenged with lipopolysaccharide (LPS). Experimental treatments were arranged in a 2 x 2 factorial, with the main effects of LPS challenge (saline vs. LPS) and dietary addition of beta-glucan (0 vs. 50 ppm). Pigs were raised individually in metabolic cages. Pigs were fed 0 or 50 ppm of beta-glucan for 28 d and then challenged with LPS (25 microg/kg of BW) or saline. After LPS injection, blood was obtained at 0, 1.5, 3, 4.5, 6, and 7.5 h to determine cytokine production and the somatotropic response. Dietary beta-glucan increased plasma interleukin-6 at 1.5, 3, and 4.5 h and tumor necrosis factor-alpha at 3 and 4.5 h and increased plasma interleukin-10 from 3 to 7.5 h after LPS challenge. The beta-glucan treatments had no effect on growth hormone. In conclusion, beta-glucan can selectively influence performance and partially offer benefits on somatotropic axis and immune function in weaned piglets challenged with LPS.
authors.affiliation: National Feed Engineering Technology Research Center, State Key Laboratory on Animal Nutrition, China Agricultural University, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: D F
authors.initials: DF
authors.lastname: Li
authors.forename: J J
authors.initials: JJ
authors.lastname: Xing
authors.forename: Z B
authors.initials: ZB
authors.lastname: Cheng
authors.forename: C H
authors.initials: CH
authors.lastname: Lai
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006854:Hydrocortisone / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008070:Lipopolysaccharides / Q000378:metabolism / Q000633:toxicity*; D008297:Male; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D013552:Swine / Q000254:growth & development* / Q000276:immunology* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D047071:beta-Glucans / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D047071:beta-Glucans; D016753:Interleukin-10; D013006:Growth Hormone; D006854:Hydrocortisone