A dose–response study to evaluate the effects of pH-stable β-mannanase derived from Trichoderma citrinoviride on growth performance, nutrient retention, and intestine morphology in broiler chickens

Figures & data

Table 1. Ingredient and composition of basal diet, as-fed basis.

Ingredients	Phase 1	Phase 2
Corn	52.74	58.41
Soybean meal	37.80	31.28
Animal fat	4.77	4.85
Tricalcium phosphate	1.84	1.66
Rapeseed meal	1.00	2.00
Limestone	0.62	0.56
d,l-methionine (84%)	0.28	0.28
l-lysine (55%)	0.26	0.28
Salt	0.20	0.20
Vitamins^a	0.15	0.15
Minerals^b	0.15	0.15
l-threonine (78%)	0.14	0.13
Choline chloride (50%)	0.05	0.05
Total	100.00	100.00
Calculated composition
ME (MJ/kg)	12.97	13.18
CP (%)	21.50	19.50
Ca (%)	0.87	0.79
Av. P (%)	0.44	0.40
Lys (%)	1.15	1.03
Met + Cys (%)	0.87	0.80
The (%)	0.77	0.69
Tryp (%)	0.18	0.16

^a Supplied per kg diet: 10,000 U vitamin A, 4500 U vitamin D₃, 65 mg vitamin E, 1.5 mg vitamin B₁, 12 mg vitamin B₂, 3.2 mg vitamin B₆, 0.011 mg vitamin B₁₂, 3.0 mg vitamin K₃, 18 mg pantotheni cacid, 60 mg niacin, 0.18 mg biotin,1.9 mg folic acid, 18 mg ethoxyquin.

^b Supplied per kg diet: 20 mg Fe, 16 mg Cu, 110 mg Zn, 120 mg Mn, 1.25 mg I, 0.9 mg Co, 0.3 mg Se.

Table 2. Effects of broilers fed diets containing graded levels of β-mannanase on growth performance and feed cost^a.

Item	β-mannanase (MNUU/kg)				SEM	p
	0	1200	2400	4800		Linear	Quadratic
1–21 d
BWG (g)	779	792	872	863	13.11	.001	.425
FI (g)	1,087	1,064	1,173	1,150	19.06	.001	.993
FCR	1.40	1.36	1.35	1.33	0.04	.215	.707
22–35 d
BWG (g)	1,339	1,360	1,387	1,376	28.95	.293	.593
FI (g)	2,537	2,504	2,547	2,518	65.30	.965	.970
FCR	1.89	1.84	1.84	1.83	0.03	.163	.501
Overall
BWG (g)	2,119	2,152	2,258	2,240	31.35	.002	.409
FI (g)	3,624	3,568	3,720	3,669	65.27	.335	.968
FCR	1.71	1.66	1.65	1.64	0.02	.033	.377
Feed cost/kg weight gain	100.0	97.25	96.56	96.46	1.38	.075	.343

^a Each mean represents values from 10 replicates (15 birds/replicate).

SEM: Standard error mean; BWG: body weight gain; FI: feed intake; FCR: feed to gain conversion ratio.

Table 3. Effects of broilers fed diets containing graded levels of β-mannanase on ileal and total tract apparent digestibility of nutrients and digesta viscosity^a.

Item	β-mannanase (MNUU/kg)				SEM	p
	0	1200	2400	4800		Linear	Quadratic
Apparent ileal digestibility (%)
Dry matter	62.74	62.87	63.42	63.38	0.75	.468	.909
N	59.75	60.48	62.33	62.41	0.56	.001	.570
Gross energy	60.48	63.64	64.38	63.92	0.71	.001	.015
Soluble NSP	19.83	22.20	24.11	24.38	0.66	.001	.119
Insoluble NSP	16.59	18.64	19.51	19.10	0.76	.014	.184
Total tract apparent retention (%)
Dry matter	71.60	72.63	73.80	73.97	0.79	.024	.590
N	60.71	61.30	62.14	61.66	0.74	.273	.470
Gross energy	64.84	66.23	67.05	67.52	0.69	.007	.508
Soluble NSP	33.55	33.27	37.07	36.26	0.78	.001	.737
Insoluble NSP	27.59	29.44	32.05	32.66	0.97	.001	.525
AMEn (MJ/kg)	10708	10938	11075	11153	115	.007	.513
Digesta viscosity (cP)	4.64	4.51	4.33	4.19	0.13	.011	.972

^a Each mean represents values from 10 replicates (four birds/replicate for ileal apparent digestibility and two birds/replicate for total tract apparent retention).

SEM: Standard error mean; NSP: none starch polysaccharides; AMEn: Apparent metabolisable energy corrected by nitrogen.

Table 4. Effects of broilers fed diets containing graded levels of β-mannanase on concentrations of monosaccharide in ileum and caecum of broilers^a.

Item	β-mannanase (MNUU/kg)				SEM	p
	0	1200	2400	4800		Linear	Quadratic
Ileum, (g/kg dry matter)
Arabinose	3.55	3.68	3.75	3.87	0.18	.198	.978
Xylose	4.02	4.01	4.13	4.21	0.11	.190	.691
Mannose	0.35	0.36	0.40	0.39	0.02	.016	.643
Galactose	6.03	6.49	6.49	6.51	0.12	.014	.079
Glucose	3.60	3.96	3.78	4.59	0.22	.003	.744
Caecum, (g/kg dry matter)
Arabinose	2.40	2.44	2.63	2.59	0.15	.260	.814
Xylose	3.90	3.79	3.97	3.92	0.08	.527	.776
Mannose	0.30	0.31	0.37	0.36	0.02	.007	.735
Galactose	5.74	6.26	6.04	6.16	0.11	.037	.075
Glucose	2.50	2.55	2.62	2.68	0.06	.017	.982

^a Each mean represents values from 10 replicates (four birds/replicate).

SEM: Standard error mean.

Table 5. Effects of broilers fed diets containing graded levels of β-mannanase on intestinal morphology^a.

Item	β-mannanase (MNUU/kg)				SEM	p
	0	1200	2400	4800		Linear	Quadratic
Villus height (µm)
Duodenum	638	640	673	687	20.94	.062	.787
Jejunum	774	801	831	835	17.47	.010	.513
Ileum	525	527	551	562	18.96	.120	.819
Crypt depth (µm)
Duodenum	423	439	427	450	14.47	.279	.826
Jejunum	468	473	503	496	16.83	.140	.744
Ileum	343	356	362	355	7.49	.213	.174
Villus height: crypt depth
Duodenum	1.51	1.46	1.60	1.54	0.07	.456	.956
Jejunum	1.66	1.70	1.68	1.71	0.06	.606	.933
Ileum	1.54	1.48	1.53	1.59	0.07	.501	.399

^a Each mean represents values from 10 replicates (two birds/replicate).

SEM: Standard error mean.