TABLE 3.

Effect of dietary TB on histomorphology of the small intestinal sections in broilers.

Item	Intestine	Control	TB1	TB2	TB3	TB4	Pooled SEM	Treatment P-value	Liner P-value	Quadratic P-value
21 days
Duodenum	Villus length (μm)	1,328.2b	1,422.4b	1,452.9ab	1,456.1ab	1,477.9a	6.86	0.05	0.42	0.16
	Crypt depth (μm)	414.0a	400.6ab	380.5ab	365.0bc	330.9c	3.77	0.00	0.03	0.01
	Villus length/crypt depth	3.21c	3.55bc	3.82b	3.99ab	4.47a	0.06	0.00	0.07	0.02
Jejunum	Villus length (μm)	926.8c	967.5bc	1,019.3ab	1,056.7a	1,071.4a	7.07	0.00	0.22	0.01
	Crypt depth (μm)	304.8a	295.00ab	291.0ab	276.7b	261.7b	1.96	0.06	0.03	0.00
	Villus length/crypt depth	3.04c	3.28b	3.50ab	3.82ab	4.09a	0.05	0.00	0.07	0.00
Ileum	Villus length (μm)	659.2c	746.1b	758.7b	794.1a	804.4a	6.69	0.00	0.35	0.08
	Crypt depth (μm)	196.5	194.0	183.5	179.7	178.3	0.97	0.64	0.28	0.06
	Villus length/crypt depth	3.35b	3.85ab	4.13ab	4.42a	4.51a	0.05	0.01	0.27	0.02
42 days
Duodenum	Villus length (μm)	1,456.0c	1,503.4bc	1,522.7b	1,545.1ab	1,614.6a	6.79	0.01	0.05	0.03
	Crypt depth (μm)	401.1a	373.6b	359.3b	368.7b	353.9b	2.14	0.01	0.45	0.29
	Villus length/crypt depth	3.63b	4.02ab	4.24ab	4.19ab	4.56a	0.04	0.00	0.21	<0.01
Jejunum	Villus length (μm)	926.8c	1,098.4b	1,127.7ab	1,119.5ab	1,170.3a	10.96	0.00	0.47	0.25
	Crypt depth (μm)	313.2a	291.8ab	287.9b	285.7b	275.1b	1.63	0.02	0.72	0.40
	Villus length/crypt depth	2.96b	3.76a	3.92a	3.92a	4.25a	0.05	0.00	0.43	0.30
Ileum	Villus length (μm)	863.6	870.5	894.5	899.2	899.9	2.32	0.72	0.59	0.15
	Crypt depth (μm)	221.0a	204.2b	200.4b	200.2b	198.9b	1.33	0.03	0.69	0.49
	Villus length/crypt depth	3.91b	4.25a	4.46a	4.49a	4.52a	0.03	0.02	0.59	0.30

SEM, standard error of the mean; TB, tributyrin. Control = basal diet; TB1 = basal diet supplemented with 230 mg/kg TB; TB2 = basal diet supplemented with 460 mg/kg TB; TB3 = basal diet supplemented with 920 mg/kg TB; TB4 = basal diet supplemented with 1,840 mg/kg TB. ^a,b,cMean values within a row with unlike superscript letters were significantly different (P < 0.05).