Table 4.

Immunohistochemistry in the duodenum and jejunum of piglets at 14 days and 35 days of experiment

Variable	Treatment1)
	NC	PC	BT	SEM	p-value*
COX-2 (%)
14 days
Duodenum	6.89a	5.59ab	2.75b	0.65	0.011
Jejunum	3.76	1.98	3.54	0.52	0.346
35 days
Duodenum	3.30	5.05	5.28	0.42	0.097
Jejunum	1.83a	1.49b	1.86a	0.06	0.020
TNF-α (average counting)
14 days
Duodenum	65.05	53.33	27.05	8.27	0.161
Jejunum	67.47	53.50	48.34	6.51	0.508
35 days
Duodenum	76.20a	63.82ab	32.49b	7.52	0.029
Jejunum	64.96	39.74	34.86	7.95	0.273

SEM, standard error of the mean; COX-2, cyclooxygenase-2; TNF-α, tumor necrosis factor α.

¹⁾NC = negative control: basal diet, PC = positive control: basal diet + colistin sulfate, BT = basal diet + butyrate- and tannin-based additive.

^*Diet effect.

^a,bDifferent letters in the same row are statistically different (p<0.05) according to Tukey’s test.