Table 6. Effect of energy level and dietary beet pulp on gut permeability index 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)
Plasma zonulin (pg/mL)	246.9	219.8	281.0	251.4	285.8	258.6	4.02	<0 .001	< 0.001	0.868	0.464	0.010	0.884
Fecal lipocalin-2 (µg/g)	24.38	23.15	25.73	23.63	24.75	22.92	0.55	0.318	0.074	0.633	0.454	0.086	0.904
Phase 2 (d 29–56)
Plasma zonulin (pg/mL)	279.9	267.1	316.5	296.5	313.5	292.1	4.17	< 0.001	0.056	0.668	0.659	0.020	0.930
Fecal lipocalin-2 (µg/g)	25.67	24.78	29.69	27.23	29.58	27.77	0.52	< 0.001	0.062	0.369	0.837	0.053	0.761

TN, thermoneutral (21°C–24°C); HS, heat stress (30°C–34°C); ME, metabolizable energy.