TABLE 1.

Effect of soluble or insoluble fiber diet without or with carbohydrases on intestinal volatile fatty acids (VFA) in weaned pigs challenged with ETEC F18^a.

Item	Treatmentb							SEM	Contrast P-valuec
	NC	PC	SF		IF			Fiber	Enzyme	F × E
			SF−	SF+	IF−	IF+
Cecal VFA, μmol/g digesta
Acetate	67.6	54.8	67.1	76.2*	44.0	40.0	5.4	<0.001	0.214	0.713
Propionate	42.6*	30.5	31.6	32.0	25.8	25.0	3.3	0.061	0.940	0.853
Butyrate	18.5	13.6	16.4	14.8	13.0	11.8	2.6	0.228	0.595	0.932
Valerate	3.7#	2.2	2.5	0.9	2.0	1.8	0.6	0.758	0.033	0.580
Total	132.4*	101.0	117.6	123.8	84.8	86.8	10.2	0.002	0.694	0.839
pH	5.59	5.55	5.41	5.18	5.44	5.58	0.24	0.219	0.785	0.282
Colonic VFA, μmol/g digesta
Acetate	62.2#	53.5	66.7*	64.9*	59.1	53.4	3.1	0.005	0.240	0.543
Propionate	22.8#	16.9	23.0*	18.6	20.4	16.6	2.0	0.256	0.046	0.870
Butyrate	12.5	9.5	15.4*	12.5	11.0	9.8	1.6	0.021	0.169	0.542
Valerate	4.2*	3.0	4.1#	3.1	3.6	2.8	0.4	0.349	0.025	0.831
Isobutyrate	2.0	1.8	0.7*	1.4	1.1	1.3	0.3	0.711	0.164	0.443
Isovalerate	3.6*	2.5	1.5#	2.3	2.0	2.3	0.4	0.524	0.152	0.414
Total	107.3*	87.1	111.7*	102.8#	97.3	86.2	5.9	0.014	0.106	0.858
pH	5.96	6.22	5.93#	5.64*	5.95#	5.91#	0.16	0.212	0.154	0.270

*Indicate significant difference compared to PC (P ≤ 0.05). ^#Indicate tendency for significant difference compared to PC (0.05 < P ≤ 0.10). ^an = 10 pigs per treatment. ^bNC, non-challenged control diet; PC, ETEC-challenged control diet; SF, soluble fiber diets without or with carbohydrases; IF, insoluble fiber diets without or with carbohydrases; SF-, soluble fiber diet without carbohydrases; SF+, soluble fiber diet with carbohydrases; IF-, insoluble fiber diet without carbohydrases; IF+, insoluble fiber diet with carbohydrases. ^cFiber, dietary fiber type effect (SF vs. IF); Enzyme, carbohydrase effect (without vs. with); F × E, fiber type by carbohydrase interaction effect.