Table 4. Effect of energy level and dietary beet pulp on short-chain fatty acid of growing-finishing pigs under heat stress conditions

Temperature (T)	TN		HS				SEM	p-value
ME (kcal/kg) (E)	3,300		3,300		3,450			3,300			HS
Fiber level (F)	Low	High	Low	High	Low	High		T	F	T × F	E	F	E × F
Phase 1 (d 0–28) (µmol/g)
Acetate	68.89	75.68	55.69	60.21	53.9	59.54	0.93	< 0.001	0.027	0.622	0.514	0.011	0.763
Propionate	13.91	15.11	11.67	12.47	11.47	13.07	0.28	< 0.001	0.041	0.665	0.722	0.041	0.489
Butyrate	7.62	9.14	5.87	6.67	6.00	6.73	0.16	< 0.001	< 0.001	0.099	0.775	0.026	0.918
Isobutyrate	3.40	2.35	3.30	3.41	3.15	3.09	0.14	0.106	0.109	0.045	0.420	0.922	0.783
Valerate	3.26	3.08	2.92	2.85	2.81	2.84	0.07	0.038	0.331	0.664	0.713	0.883	0.726
Isovalerate	4.77	4.89	4.63	4.14	4.25	4.21	0.12	0.117	0.491	0.259	0.540	0.293	0.379
Total SCFA	104.4	112.36	85.07	92.18	82.65	89.48	1.42	< 0.001	0.023	0.607	0.375	0.021	0.960
Phase 2 (d 29–56) (µmol/g)
Acetate	80.38	84.54	60.76	63.36	60.09	63.73	0.64	< 0.001	0.020	0.548	0.908	0.022	0.686
Propionate	15.26	16.96	12.19	13.74	12.67	13.67	0.27	< 0.001	0.008	0.887	0.704	0.027	0.622
Butyrate	8.75	10.37	6.04	7.08	6.02	7.10	0.22	< 0.001	0.004	0.454	0.996	0.027	0.973
Isobutyrate	2.57	2.57	3.62	3.55	3.61	3.51	0.01	< 0.001	0.457	0.485	0.411	0.006	0.728
Valerate	3.72	3.48	2.99	3.25	2.95	3.13	0.04	< 0.001	0.920	0.013	0.422	0.034	0.687
Isovalerate	6.10	5.49	4.26	4.54	4.23	4.77	0.09	< 0.001	0.465	0.061	0.616	0.045	0.532
Total SCFA	118.1	124.6	89.91	95.69	89.88	96.32	0.91	< 0.001	0.018	0.465	0.948	0.026	0.572

TN, thermoneutral (21°C–24°C); HS, heat stress (30°C–34°C); ME, metabolizable energy; SCFA, short-chain fatty acid.