Table 7. Effect of dietary treatments on small intestine histometric of male broiler chicks at 10 days of age

Item	Dietary treatments¹⁾						SEM	p-value
Item	T1	T2	T3	T4	T5	T6	SEM	GA	L	Q
Duodenum
VL (μm)	833^b	1,077^a	904^a	975^a	1054^a	1025^a	16.9	< .0001	< .0001	0.047
W (μm)	148^b	159^b	162^a	154^b	157^b	137^b	3.80	< .0001	0.161	< .0001
SA (mm²)	0.39^b	0.54^a	0.46^a	0.47^a	0.52^a	0.44^a	0.01	< .0001	< .0001	< .0001
VL/CD	8.8^b	13.2^a	14.0^a	10.2^a	12.7^a	12.2^a	0.30	< .0001	< .0001	< .0001
GC (no)	109^b	128^a	106^b	107^b	103^b	88^c	2.64	< .0001	0.045	0.186
GC100‎	6.6^a	5.9^b	6.0^a	5.6^b	4.9^b	4.3^b	0.15	< .0001	< .0001	0.398
ET (μm)	36.8^b	35.2^b	31.9^c	36.9^b	41.9^a	37.9^b	0.86	< .0001	0.511	0.054
LPT (μm)	53.3^a	48.2^b	42.1^b	46.1^b	42.5^b	47.7^b	1.31	< .0001	< .0001	< .0001
Jejunum
VL (μm)	744^b	1108^a	997^a	918^a	996^a	1026^a	19.2	< .0001	< .0001	< .0001
W (μm)	146^b	166^a	158^b	176^a	155^b	136^b	4.07	< .0001	0.009	< .0001
SA (μm²)	0.34^b	0.58^a	0.49^a	0.50^a	0.48^a	0.44^a	0.01	< .0001	< .0001	< .0001
VL/CD	8.6^b	14.0^a	12.6^a	13.4^a	15.4^a	13.9^a	0.36	< .0001	< .0001	< .0001
GC (no)	91^b	142^a	117^a	128^a	131^a	109^a	3.82	< .0001	< .0001	< .0001
GC100‎	6.2^a	6.5^a	6.0^a	7.2^a	7.1^a	5.3^b	0.27	< .0001	0.517	0.001
ET (μm)	37.3^b	44.4^a	38.4^b	42.8^a	38.0^b	33.8^b	1.07	< .0001	0.058	< .0001
LPT (μm)	53.6^b	63.0^a	55.2^b	51.0^b	49.6^b	36.1^c	1.39	< .0001	0.091	< .0001
Ileum
VL (μm)	518^b	896^a	626^a	600^a	800^a	544^b	21.4	< .0001	< .0001	< .0001
W (μm)	104^b	134^a	168^a	116^b	161^a	115^b	4.50	< .0001	< .0001	< .0001
SA (μm²)	0.17^b	0.37^a	0.33^a	0.22^a	0.39^a	0.20^b	0.01	< .0001	< .0001	< .0001
VL/CD	9.2^b	11.8^a	9.2^b	9.2^b	12.1^a	8.9^b	0.35	< .0001	0.010	0.053
GC (no)	77^b	101^a	82^b	111^a	119^a	89^a	2.84	< .0001	< .0001	< .0001
GC100)‎	7.6^b	5.9^c	6.7^b	9.3^a	8.2^b	8.2^b	0.29	< .0001	0.963	0.695
ET (μm)	28.3^b	35.8^a	29.2^b	30.4^b	34.2^a	30.8^b	0.79	< .0001	< .0001	0.100
LPT (μm)	32.9^b	39.5^a	38.9^a	37.6^a	49.6^a	39.4^b	1.10	< .0001	< .0001	0.002

Dietary treatments from T1 to T6 supplemented by 0.0%, 0.12%, 0.25%, 0.50%, 0.75%, and 1.0% of gum Arabic, respectively.
Means that do not share a common superscripted with control treatment (T1) within a row for each parameter has a significant effect, as determined by the Dunnett test (p < 0.05).
SEM, standard error of means for diet effect; GA, gum Arabic levels effect; L, linear response; Q, quadratic response; VL, length; W, width; SA, villus surface area (mm²); VL/CD, villus length/crypt depth; GC, goblet cells; GC/100, goblet cells / 100 µm villi area; ET, epithelial thickness; LPT, lamina propria thickness.