A soluble and highly fermentable dietary fiber with carbohydrases improved gut barrier integrity markers and growth performance in ETEC challenged pigs

Authors: LI, QINGYUN - Iowa State University; BURROUGH, ERIC - Iowa State University; GABLER, NICHOLAS - Iowa State University; Loving, Crystal; TUGGLE, CHRISTOPHER - Iowa State University; SAHIN, ORHAN - Iowa State University; GOULD, STACIE - Iowa State University; PATIENCE, JOHN - Iowa State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2018
Publication Date: 3/19/2019
Citation: Li, Q., Burrough, E.R., Gabler, N.K., Loving, C.L., Sahin, O.A., Gould, S.A., Patience, J.F. 2019. A soluble and highly fermentable dietary fiber with carbohydrases improved gut barrier integrity markers and growth performance in F18 ETEC challenged pigs. Journal of Animal Science. 97(5):2139-2153. https://doi.org/10.1093/jas/skz093.
DOI: https://doi.org/10.1093/jas/skz093

Interpretive Summary: Pork is an important protein source, and is in high demand globally. Post-weaning diarrhea, caused by enterotoxigenic E. coli (ETEC) causes significant production loss in the swine nursery. Dietary additives may be one method to limit disease and improve growth during ETEC infection. Dietary soluble and insoluble fiber formulated with and without different enzymes are commonly added to nursery diets to improve diet digestiblity. The addition of an enzyme blend to a soluble fiber diet in nursery age pigs provided a benefit after ETEC infection, as the pigs on the diet had improved performance compared to pigs receiving a control diet. Pigs fed insoluble fiber without the addition of enzymes had increased incidence of diarrhea and more E. coli in the feces, suggesting that dietary fiber can impact ETEC disease in pigs. Collectively, the results provide useful information to pork producers on methods to enhance efficiency of their production systems when faced with ETEC issues in the nursery.

Technical Abstract: This study aimed to evaluate the effects of a source of dietary soluble (SF) and insoluble fiber (IF) without or with exogenous carbohydrases (xylanase, beta-glucanase, and pectinase) on diarrhea incidence, selected immune responses, and growth performance in enterotoxigenic E. coli (ETEC)-challenged pigs. Sixty weaned pigs (6.9 plus/negative 0.1 kg BW, approximately 23-d of age) were blocked by initial BW and placed in individual pens. Pens were randomly assigned to 1 of 6 treatments (n equals 10 per treatment), including a non-challenged control (NC), a positive challenge control (PC), the PC+ a soluble fiber diet (10 percent sugar beet pulp) without (SF-) or with carbohydrases (SF+), and PC+ an insoluble fiber diet (15 percent corn distillers dried grains with solubles) without (IF-) or with carbohydrases (IF+). The control diet was primarily based on corn and soybean meal with 13.5 percent whey powder. The 2 sources of fiber were added at the expense of cornstarch in the control diet. Pigs were orally inoculated with 6 mL hemolytic F18 ETEC (approximately 3.5 × 10**9 cfu/mL) or sham infected with 6 mL phosphate-buffered saline on d 7 (0 d post inoculation, dpi) post weaning. All ETEC challenged pigs were confirmed to be genetically susceptible to F18 ETEC. Pigs had free access to feed and water throughout the 14-d trial. Pig BW and feed intake were recorded on dpi -7, 0, and 7 or 8. Fecal swabs were collected on dpi -7, 0, 1, 2, 3, 5, and 7 or 8 to evaluate hemolytic E. coli shedding. Fecal score was visually ranked daily post-challenge to evaluate diarrhea incidence. Blood samples were collected on dpi -1, 3, and 7 or 8 at necropsy and intestinal tissues were collected at necropsy. Pigs on PC had lower dpi 1 to 7 ADG and ADFI than those on NC (P less than 0.05). Compared with PC pigs, SF+ pigs had greater ADG during both pre- and post-challenge period (P less than 0.05). The IF- increased post-challenge diarrhea incidence compared with PC (P less than 0.05). Pigs on SF- had lower ileal E. coli attachment than PC (P less than 0.05). The SF+ reduced haptoglobin and IF+ reduced C-reactive protein on dpi 3 compared to PC (P less than 0.05). Compared with PC pigs, SF+ pigs tended to have lower ileal TNF alpha and greater ileal occludin (OCLN) mRNA (P less than 0.10) and had greater (P less than 0.05) colonic OCLN mRNA levels. Collectively, IF- increased incidence of diarrhea and fecal E. coli shedding compared with PC. The SF+ pigs had improved growth compared with PC pigs, likely due in part to a reduction in inflammatory intermediates.