. 2020 Dec 2;7:601336. doi: 10.3389/fvets.2020.601336

Table 4.

Effect of dietary supplementation with graded levels of algae-derived polysaccharides (ADP) on intestinal morphology in broiler chickens.

Items	Dietary ADP levels (mg/kg)						SEM	p-value
	0	1,000	2,500	4,000	5,500	7,000		Linear	Quadratic
DAY 21
DUODENUM
Villus height, μm	430.68^a	471.42^a,b	464.00^a,b	558.38^b	559.75^b	465.56^a,b	26.80	0.004	0.335
Crypt depth, μm	101.80	113.03	108.49	100.89	135.71	103.32	17.75	0.928	0.600
Villus height-to-crypt depth ratio	4.59	4.65	4.36	5.72	4.82	4.82	0.66	0.309	0.337
Villus width, μm	61.55^a	73.84^a,b	77.29^a,b	92.08^b	89.96^b	73.47^a,b	7.71	0.011	0.873
Villus surface area, mm²	0.086^a	0.110^a,b	0.115^a,b	0.162^b	0.162^b	0.108^a,b	0.016	0.003	0.469
JEJUNUM
Villus height, μm	369.93^a	439.85^b	450.57^b	451.98^b	437.79^a,b	446.00^b	23.87	0.024	0.164
Crypt depth, μm	94.509	91.327	101.058	108.95	107.66	100.51	9.91	0.243	0.581
Villus height-to-crypt depth ratio	4.26	4.98	4.56	4.30	4.20	4.61	0.48	0.891	0.324
Villus width, μm	68.40	80.61	91.99	79.40	73.51	76.19	10.33	0.346	0.242
Villus surface area, mm²	0.079^a	0.110^a,b	0.128^b	0.111^a,b	0.101^a,b	0.108^a,b	0.014	0.094	0.119
ILEUM
Villus height, μm	226.84^a	255.85^a,b	302.26^b	269.52^a,b	302.03^b	281.13^b	18.42	0.044	0.106
Crypt depth, μm	64.86	59.35	77.08	69.52	75.04	75.91	6.97	0.319	0.884
Villus height-to-crypt depth ratio	3.77	4.50	4.07	4.08	4.25	3.79	0.50	0.833	0.475
Villus width, μm	62.64	71.88	60.30	63.69	60.33	60.19	6.55	0.776	0.660
Villus surface area, mm²	0.044	0.056	0.057	0.053	0.057	0.05	0.005	0.215	0.151
Day 35
DUODENUM
Villus height, μm	817.01^a	896.55^b	883.50^a,b	945.72^b	940.42^b	893.72^b	25.26	0.003	0.737
Crypt depth, μm	210.47	192.70	209.16	194.48	205.37	192.48	9.61	0.383	0.820
Villus height-to-crypt depth ratio	3.93^a	4.75^b	4.24^a,b	4.88^b	4.59^a,b	4.68^b	0.25	0.046	0.734
Villus width, μm	165.34	174.51	179.96	178.41	162.12	186.60	9.56	0.313	0.587
Villus surface area, mm²	0.423^a	0.492^a,b	0.504^a,b	0.531^b	0.480^a,b	0.523^b	0.031	0.025	0.507
JEJUNUM
Villus height, μm	569.58	638.70	634.24	610.09	611.92	608.45	23.99	0.275	0.065
Crypt depth, μm	152.00	158.36	157.73	165.12	169.40	162.13	10.25	0.407	0.960
Villus height-to-crypt depth ratio	3.92	4.09	4.05	3.77	3.65	3.79	0.29	0.717	0.442
Villus width, μm	111.74	115.44	117.65	99.07	95.51	115.19	10.12	0.437	0.281
Villus surface area, mm²	0.200	0.231	0.232	0.189	0.182	0.223	0.021	0.723	0.084
ILEUM
Villus height, μm	313.22^a	360.21^a,b	404.40^b	372.62^b	398.49^b	373.01^b	20.03	0.022	0.064
Crypt depth, μm	113.06	110.82	113.85	108.95	115.69	114.81	9.06	0.820	0.885
Villus height-to-crypt depth ratio	2.82	3.30	3.61	3.50	3.81	3.41	0.42	0.222	0.482
Villus width, μm	97.95	111.03	99.56	96.22	93.70	99.13	7.53	0.626	0.286
Villus surface area, mm²	0.093^a	0.124^b	0.126^b	0.111^a,b	0.117^b	0.115^a,b	0.008	0.115	0.007

SEM, standard error of the mean.

^a,b

Means in the same row with different superscripts differ (P < 0.05).