Supplemental vitamin C and yeast cell wall beta-glucan as growth enhancers in newborn pigs and as immunomodulators after an endotoxin challenge after weaning.
To test possible dietary immune modulators, 32 crossbred male pigs were given 1 of 4 dietary treatments (8 pigs/treatment): control, Saccharomyces cerevisiae with beta-glucan (Energy Plus, Natural Chem Industries LTD, Houston, TX; 0.312 g/kg of BW, 2.5% of diet), vitamin C (Stay C 35, DSM Nutritional Products Inc., Prisippany, NJ; 75 ppm), or beta-glucan plus vitamin C together (combination; 0.312 g/kg of BW and 75 ppm, respectively). Supplements were given in whole milk within 36 h of birth and then daily for 2 wk until weaning, when the supplement was given in feed for an additional 2 wk. Growth was recorded during the 4 wk of supplement delivery. An i.v. lipopolysaccharide challenge (LPS; 150 microg/kg) was given 14 d postweaning at 0900. Behavior was observed, and blood samples were collected every 30 min for 4 h via a jugular catheter from -1 (0800) to 3 (1200) h relative to challenge (-60, -30, 0, 30, 60, 90, 120, 150, and 180 min), and tissues were collected after exsanguination. Beta-glucan (glucan and combination) increased (P < 0.05) BW and ADG compared with vitamin C and control. Cortisol concentrations showed an interaction (P < 0.05) of the beta-glucan and vitamin C. Intestinal expression of tumor-necrosis factor (TNF)-alpha mRNA was greatest for vitamin C and beta-glucan compared with control and combination, and liver TNF-alpha mRNA expression showed a main effect (P < 0.01) of beta-glucan. Lung expression of TNF-alpha mRNA exhibited a vitamin C effect (P < 0.01). In contrast, spleen had greater (P < 0.01) relative abundance of TNF-alpha mRNA in beta-glucan pigs. Intestinal expression of IL-1Ra mRNA was greater (P < 0.05) for vitamin C and beta-glucan treatments compared with the control and combination pigs. Liver expression of IL-1 receptor antagonist mRNA exhibited a vitamin C effect (P < 0.01). Lying and sleeping behaviors differed (P < 0.05) among treatments early in the observations (0700 to 0720), then sporadically until 50 min after the LPS injection. The vitamin C group slept less (P < 0.05) on those occasions. The time spent lying was least (P < 0.05) for the glucan and combination pigs immediately after the injection. These results show a complex interaction between vitamin C and this yeast product after LPS challenge, with differential expression in tissues by 2 h after LPS injections. The combination enhanced postweaning growth and reduced TNF-alpha expression of the intestinal and liver tissues, suggesting an important immunomodulatory role of the combination treatment.
Eicher
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SD
Livestock Behavior Research Unit, USDA-ARS, West Lafayette, IN 47907, USA. spruiett@purdue.edu
McKee
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Carroll
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Pajor
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D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D002473:Cell Wall / Q000737:chemistry; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D007155:Immunologic Factors / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D008351:Mannans / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae; D013552:Swine / Q000254:growth & development*; D014886:Weaning; D047071:beta-Glucans / Q000494:pharmacology*
D007155:Immunologic Factors; D008070:Lipopolysaccharides; D008351:Mannans; D047071:beta-Glucans; C022901:(1-6)-alpha-glucomannan; D001205:Ascorbic Acid