Effect of sodium butyrate on growth performance and response to lipopolysaccharide in weanling pigs

¹ USDA-ARS, National Swine Research and Information Center, Ames, IA, 50011-3310

^* To whom correspondence should be addressed. E-mail: weberte{at}nsric.ars.usda.gov.

	Abstract

Two experiments were conducted to determine effects of dietary sodium butyrate on growth performance and response to Escherichia coli. lipopolysaccharide (LPS) in weanling pigs. In a 28-d experiment, 180 pigs (initial BW 6.3 kg) were fed 0, 0.05, 0.1, 0.2, and 0.4% sodium butyrate, or 110 mg/kg dietary tylosin. There was no effect of dietary sodium butyrate or tylosin on overall G:F, but there was a linear trend (P < 0.07) towards decreased ADFI and ADG as levels of sodium butyrate increased. In a second 28-d experiment, 108 pigs (initial BW 6.3 kg) were assigned to 3 dietary treatments: 1) no antibiotics, 2) 0.2% sodium butyrate, or 3) 55 mg/kg carbadox. On d 14, a subset of pigs from the no antibiotic and butyrate treatment groups was challenged with E. coli LPS or injected with sterile saline in a 2 x 2 factorial arrangement (± LPS challenge; ± dietary butyrate; n = 6 pigs/treatment group). Four hours after LPS challenge, blood samples were obtained, and samples of LM, liver, and ileum were collected for gene expression analysis. Serum samples were analyzed for IL-6, tumor necrosis factor (TNF), ₁-acid glycoprotein, cortisol, IGF-I, insulin, and metabolites. The relative abundance of tissue cytokine and IGF-I mRNA was measured by real-time PCR. Feeding diets containing sodium butyrate or carbadox did not alter ADG or ADFI compared to pigs fed the control diet. From d 0 to d 14, pigs fed diets containing 0.2% sodium butyrate had decreased (P < 0.05) ADG and tended (P < 0.06) to have decreased G:F compared to animals fed diets containing carbadox. Challenge with LPS increased (P < 0.05) serum cytokines and cortisol and decreased (P < 0.05) serum glucose and triglycerides. Injection with LPS increased (P < 0.05) the relative abundance of hepatic IL-6 and TNF mRNAs, increased (P < 0.05) LM TNF mRNA content, and decreased (P < 0.05) IGF-I mRNA in LM. For serum cortisol, there was an interaction (P < 0.05) between dietary butyrate and LPS. The increase in serum cortisol due to LPS was greater (P < 0.05) in pigs fed butyrate than pigs fed the control diet. There tended (P < 0.10) to be an interaction between LPS and diet for butyrate to increase the relative abundance of IL-6 mRNA in LM. Carbadox did not alter cytokine or IGF-I mRNAs or serum metabolites, but did decrease (P < 0.05) serum TNF. These data indicate that dietary sodium butyrate does not enhance growth performance, but may regulate the response to inflammatory stimuli in weanling pigs.

Key Words: butyrate, growth performance, lipopolysaccharide, weanling pig