Soluble Fiber Improved Growth Performance of Weaned Pigs Challenged with Enterotoxigenic Escherichia coli

Our objective was to evaluate the effects of soluble (10% beet pulp) versus insoluble dietary fiber (15% low-fat corn DDGS) with or without addition of exogenous carbohydrases on fecal score and shedding as well as performance of piglets challenged with enterotoxigenic Escherichia coli (ETEC). Sixty piglets (approximately 21-d age; 6.90 ± 0.07 kg) were randomly allotted to 6 treatments including: 1) NC: non-challenged negative control, 2) PC: F18 ETEC challenged positive control (NE=2.68 Mcal/kg), 3) SF: soluble fiber + ETEC (NE=2.53 Mcal/kg), 4) IF: insoluble fiber + ETEC (NE=2.50 Mcal/kg), and 5, 6) SF or IF with enzymes + ETEC. The soluble fiber content in control, SF and IF was 3.20, 5.43, and 2.87%, and 5.04, 9.56, and 10.16% for insoluble fiber, respectively. Pigs were orally challenged with ETEC on d 7 (0 d post inoculation, dpi). Pigs were housed individually to record individual BW and feed intake on d 7, 10, and 14. Fecal swabs were collected to evaluate viable ETEC shedding score (SS: ranged from 0-4 with increasing shedding). Fecal scores (FS) were visually ranked every 2 d pre-challenge and daily post-challenge using 4 scales: 1=solid; 4=liquid. Fecal score were analyzed using a multinomial model in PROC GENMOD and all other data were analyzed using PROC MIXED of SAS (9.4). Pigs in PC had lower final BW (8.57 vs.9.90 kg) and overall ADG (128 vs.218 g) than NC (P<0.05). The SF improved ADG from 4-7 dpi (333 vs.182 g) and overall ADG (224 vs.128 g) compared with PC (P<0.05). The SF and IF improved G:F pre-challenge (P<0.01) and SF tended to improve G:F post-challenge (P<0.10). Enzymes had no impact on growth (P>0.05). The average SS in NC was lower than PC (0 vs. 2.46;P<0.01). The IF tended to increase SS on 3 dpi (3.05 vs.2.00;P=0.065) and decreased SS on 7 dpi (1.85 vs.3.13;P<0.05) compared to PC. Pigs in SF tended to have a lower SS on 7 dpi (2.10 vs.3.13;P=0.071) than PC. The SF reduced SS on 3 and 5 dpi compared with IF (P<0.05). During 1-3 dpi, the odds ratio (OR) of NC in lower FS category was 3.96 times higher than IF (P<0.01). From 4-7 dpi, IF, but not SF, reduced the lower FS OR of PC by 54% (P<0.05). In conclusion, SF, but not IF, regardless of enzyme addition, improved performance of pigs challenged with F18 ETEC, without affecting fecal ETEC shedding and fecal scores.