Table 9.

Relative mRNA expression of antioxidation and tight junction related genes in broiler jejunum on d 42.

Stocking density	Methionine (%)	SOD	GPX	Claudin-3	Occludin
LSD	0.35	1.51	11.01	4.26	2.42
	0.40	1.67	12.36	3.87	3.00
	0.45	1.48	10.20	3.06	2.30
	0.50	1.50	10.76	2.15	2.28
HSD	0.35	1.43	10.68	3.71	2.17
	0.40	1.63	8.83	4.53	3.01
	0.45	1.39	10.51	3.71	2.75
	0.50	1.97	11.67	2.61	2.11
	SEM	0.096	0.838	0.359	0.120
Main effect analysis
Stocking density	LSD	1.54	11.08	3.40	2.50
	HSD	1.60	10.51	3.64	2.46
Methionine	0.35	1.47	10.85	3.99a	2.28b
	0.40	1.65	10.79	4.20a	3.01a
	0.45	1.43	10.36	3.39ab	2.52ab
	0.50	1.73	11.22	2.41b	2.19b
P-value
Stocking density × Methionine		0.314	0.760	0.485	0.428
Stocking density		0.605	0.672	0.353	0.929
Methionine		0.207	0.981	0.002	0.012

Means in the same column lacking a common superscript differ (P < 0.05). The specific stocking density is: LSD 14 broilers/m², HSD 20 broilers/m².

Abbreviations: GPX, glutathione peroxidase; HSD, high stocking density; LSD, low stocking density; MDA, malondialdehyde; SOD, superoxide dismutase.