Table 5.

Effect of adding BP and colistin to the diets on histological changes of jejunum in exposed chickens.

Morphometric parameters	Dietary treatments					SEM	P-value1
	Control	0.3 g colistin	0.4 g colistin	1.0 g BP	1.5 g BP		Trt	C vs BP	Lin	Quad
7 day post-challenge
Villus height (µm)	621.00b	636.90b	838.30a	761.20ab	799.30ab	44.359	0.003	0.023	0.022	0.748
Crypt depth (µm)	92.52a	71.39b	90.29a	89.95a	82.56ab	4.233	0.008	0.258	0.152	0.463
VH: CD	6.65b	8.90a	9.46a	8.51ab	9.78a	0.511	0.001	0.001	0.000	0.750
Villus width (µm)	90.54	85.41	91.88	91.54	97.28	4.053	0.379	0.328	0.191	0.406
VSA (mm2)	0.17b	0.17b	0.24a	0.21ab	0.24a	0.014	0.001	0.009	0.006	0.978
Muscle thickness (µm)	200.80ab	171.70b	249.90a	250.40a	255.00a	15.881	0.001	0.025	0.029	0.545
14 day post-challenge
Villus height (µm)	794.43	917.87	812.42	841.58	945.81	43.302	0.077	0.105	0.048	0.376
Crypt depth (µm)	108.47	99.63	100.20	101.84	100.19	4.964	0.702	0.244	0.241	0.862
VH: CD	7.39	9.32	8.19	8.40	9.57	0.581	0.079	0.049	0.025	0.568
Villus width (µm)	108.30	112.48	108.82	108.74	111.95	4.676	0.946	0.699	0.592	0.712
VSA (mm2)	0.26	0.32	0.27	0.28	0.33	0.019	0.104	0.112	0.050	0.355
Muscle thickness (µm)	185.68b	254.90a	195.82b	236.45ab	251.70a	12.389	0.000	0.001	0.000	0.665

0.3 g colistin: 0.3 g/kg colistin in diet; 0.4 g colistin: 0.4 g/kg colistin in diet; 1 g BP: 1 g/kg bacteriophage in diet; 1.5 g BP: 1.5 g/kg bacteriophage in diet.

VH: CD villus height to crypt depth ratio; VSA villus surface area.

¹Trt: overall effects of treatments; C vs BP: contrasting birds not treated with BP or colistin versus birds treated with BP; Lin: linear effects of increasing inclusion levels of BP; Quad: quadratic effects of increasing inclusion levels of BP.

^abcValues within a row followed by different superscripts are significantly different. P < 0.05; Tukey's pairwise test.