Fig 4. LT gene abundance determined by qPCR in the feces of INF-CO, INF-TA, NINF-CO, and NINF-TA piglets at days 0 and 4 post infection.

Data are expressed as Log₁₀ (1+Y), where Y represents the ng LT-DNA per g feces. P-values of the Wilcoxon test for the main factors at day 0: infection: P = 1.00; feed: P = 0.26; and at day 4: infection: P = 0.009; diet: P = 0.34. ^A,B indicates differences between infected and noninfected piglets at P = 0.009 on day 4. Piglets in the INF-CO and INF-TA groups were infected orally with 5 ml of the ETEC F4 suspension containing 10⁸ CFU/ml four days post weaning and fed either an unsupplemented standard control starter diet or a control standard diet supplemented with 1% chestnut-tannin extract from weaning (day -4) for 18 days, respectively. Piglets in the NINF-CO and NINF-TA groups were fed the same diets for the same time span as previously described but received 5 ml of PBS orally.