Table 4.

Means of fluorescein isothiocyanate dextran (FITC-d, μg/mL), superoxide dismutase (SOD, U/µg) and glutathione peroxidase (GPx, mmol/min/g) activity, reduced glutathione (GSH, mmole/g) and oxidized glutathione (GSSG, mmole/g) concentration and their ratio (GSH:GSSG), and the gene expression of claudin-1 (CLDN-1), occludin, and mucin-2 (Muc-2) of unchallenged control (0% DTB) and broilers fed 0, 0.125, 0.25, or 0.5% DTB challenged with Eimeria spp. at 20 or 26 d of age.

		Treatment					P value	Contrasts		SE
Variables		Unchallenged control	Challenged control	0.125% DTB	0.25% DTB	0.5% DTB		L1	Q
FITC-d		−0.008b	0.241a	0.222a	0.269a	0.282a	<0.001	0.423	0.915	0.0424
Gene expression
20 d (6 dpi)	CLDN-1	1.000	2.775	2.788	1.369	2.074	0.117	0.310	0.336	0.5768
	Occludin	1.000a	0.904b	0.807c	0.882bc	0.829bc	0.014	0.422	0.720	0.0399
	Muc-2	1.000a	0.669b	0.550c	0.588bc	0.610bc	<0.001	0.611	0.112	0.0398
26 d (12 dpi)	CLDN-1	1.000	1.298	1.228	1.010	0.869	0.101	0.017	0.791	0.1287
	Occludin	1.000	0.991	0.989	0.960	0.886	0.486	0.109	0.658	0.0525
	Muc-2	1.000a	0.884b	0.897ab	0.752c	0.724c	0.001	0.011	0.751	0.0512
Antioxidant system
20 d (6 dpi)	SOD	5.570	5.748	5.502	5.595	5.495	0.742	0.373	0.635	0.1536
	GPx	0.027c	0.036b	0.042a	0.041ab	0.037b	<0.001	0.715	0.052	0.0022
	GSH	4.271a	3.241b	2.831b	2.836b	2.828b	<0.001	0.401	0.412	0.2723
	GSSG	0.290	0.514	0.521	0.343	0.277	0.234	0.060	0.895	0.1236
	GSH:GSSG	18.006	9.091	10.959	19.423	15.820	0.689	0.407	0.460	7.7108
26 d (12 dpi)	GSH	3.784ab	3.294bc	3.966a	3.145c	2.729c	0.005	0.021	0.177	0.2443
	GSSG	0.312	0.212	0.241	0.293	0.356	0.783	0.182	0.959	0.1184
	GSH:GSSG	29.662	40.963	65.709	17.668	7.723	0.110	0.068	0.699	23.3339

^a,b,cMeans followed by superscript letters are different by Tukey's test (P < 0.05; P < 0.10) within the row.

¹L, linear effect; Q, quadratic effect.

SE = pooled standard error.