Effects of feed form and xylanase supplementation on performance and ileal nutrients digestibility of heat-stressed broilers fed wheat–soybean diet

Figures & data

Table 1. Ingredients and calculated and analysed compositions of the basal diets.

Item	Grower (0–21 d)	Finisher (22–42 d)
Ingredients (%)
Wheat (12.5% CP)	50.55	51.00
Corn	14.00	19.32
Soybean meal (48% CP)	29.00	22.00
Soybean oil	2.50	4.00
Limestone	1.10	1.00
Dicalcium phosphate	1.70	1.50
NaHCO3	0.20	0.20
Salt	0.15	0.10
L-Lysine	0.20	0.22
DL-Methionine	0.14	0.13
L-Threonine	0.05	0.03
Vitamin–Mineral premix^a	0.50	0.50
Calculated composition
Metabolizable energy (MJ/kg)	12.18	12.81
Available phosphorus (g/kg)	4.5	4.0
Lysine (%)	1.25	1.07
Methionine (%)	0.45	0.41
Methionine + Cystine (%)	0.90	0.80
Analysed composition (g/kg)
Crude protein (N×6.25)	21.15	18.53
Total phosphorus (%)	0.69	0.60
Calcium (%)	0.90	0.80

^aVitamin and mineral premix supplied the following per kilogram of diet: vitamin A (from vitamin A acetate), 10,000 IU; vitamin D₃, 9790 IU; vitamin E (dl-α-tocopheryl acetate), 30 IU; vitamin B₁₂, 20 μg; riboflavin, 4.4 mg; calcium pantothenate, 40 mg; niacin, 22 mg; choline, 840 mg; biotin, 30 μg; thiamin, 4 mg; zinc sulfate, 60 mg; copper sulfate, 100 μg; selenium (sodium selenate), 0.2 mg; iodine, 1 mg; manganese oxide, 60 mg.

Figure 1. Effects of feed form and xylanase supplementation and their interaction effect on average EBI in broiler chickens at 42 days of age. Means without a common superscript (a–c) differ significantly (P  < .05).

Table 2. Effects of feed form and xylanase enzyme on average daily gain (ADG), average daily feed intake(ADFI), and feed conversion ratio (FCR) of heat-stressed broilers fed wheat-based diet (n  = 5).

Treatments	ADG (g/d)			ADFI (g/d)			FCR (g/g)
	0–21 d	22–42 d	0–42 d	0–21 d	22–42 d	0–42 d	0–21 d	22–42 d	0–42 d
Mash	25.3^b	57.1^b	41.2^c	38.4^c	114.2^c	76.3^c	1.52^b	2.00^a	1.85
Mash + xylanase	27.4^b	58.7^b	43.1^bc	40.2^c	116.4^c	78.3^c	1.46^b	1.98^ab	1.82
Crumble	29.5^ab	61.1^ab	45.3^b	43.2^b	119.7^b	81.4^b	1.47^b	1.96^b	1.80
Crumble + xylanase	28.3^ab	62.7^a	45.5^b	45.8^b	121.5^b	83.7^b	1.62^a	1.94^b	1.84
Pellets	31.2^a	62.3^a	46.8^ab	48.7^a	127.6^a	88.2^a	1.56^a	2.05^a	1.88
Pellets + xylanase	33.6^a	64.5^a	49.1^a	49.3^a	129.5^a	89.4^a	1.47^b	2.01^a	1.82
SEM	0.14	0.28	0.19	0.44	1.26	0.57	0.013	0.024	0.023
Main effects
Feed form
Mash	26.4^b	57.9^c	42.1^c	39.3^c	115.3^c	77.3^c	1.49^b	1.99^ab	1.84
Crumbles	28.9^ab	61.9^b	45.4^b	44.5^b	120.6^b	82.5^b	1.54^a	1.95^b	1.82
Pellets	32.4^a	63.4^a	47.9^a	49.0^a	128.5^a	88.8^a	1.51^ab	2.03^a	1.85
Xylanase
−	28.6	60.2^b	44.4^b	43.4^b	120.5	82.0	1.52	2.00	1.85
+	29.8	61.9^a	45.9^a	45.1^a	122.5	83.8	1.83	1.98	1.83
SEM	0.14	0.27	0.19	0.4	1.2	0.5	0.01	0.02	0.02
P-value
Feed form	0.005	<0.001	0.004	0.006	<0.001	0.002	0.021	0.037	0.13
Xylanase	0.16	0.045	0.038	0.041	0.23	0.27	0.32	0.45	0.36
Feed form × xylanase	0.08	0.07	0.09	0.32	0.13	0.37	0.16	0.17	0.11

Note: Mean values within a column with different letters differ significantly (P  < .05).

Table 3. Effects of feed form and xylanase enzyme on carcass weight (CW), carcass yield (CY), and abdominal fat-to-carcass weight ratio (AF:CW) of heat-stressed broilers fed wheat-based diet (n  = 5).

Treatments	CW (g)	CY (%)	AF:CW
Mash	1096	62.30	1.64
Mash + xylanase	1176	63.95	1.69
Crumble	1279	66.22	2.23
Crumble + xylanase	1290	66.53	2.28
Pellets	1357	68.05	2.32
Pellets + xylanase	1423	68.08	2.36
SEM	14.5	2.72	0.06
Main effect
Feed form
Mash	1145^c	63.12^b	1.67^b
Crumbles	1294^b	66.38^ab	2.26^a
Pellets	1400^a	68.06^a	2.34^a
Xylanase
−	1251	65.52	2.06
+	1304	66.19	2.11
SEM	14.3	2.72	0.07
P-value
Feed form	0.006	0.011	0.003
Xylanase	0.086	0.253	0.541
Feed form × xylanase	0.126	0.412	0.328

Note: Mean values within a column with different letters differ significantly (P  < .05).

Table 4. Effects of feed form and xylanase enzyme on ileal digestibility of apparent metabolizable energy corrected to zero nitrogen retention (AMEn), crude protein (CP), Ca, and phosphorus (P) of heat-stressed broilers fed wheat-based diet (n  = 5).

Treatments	AMEn (MJ/kg)	CP (%)	Ca (%)	P (%)
Mash	11.37^c	80.4^b	58.1^b	38.5
Mash + xylanase	11.61^a	82.0^ab	59.2^a	39.4
Crumble	11.47^b	81.2^ab	58.4^ab	38.0
Crumble + xylanase	11.69^a	84.5^a	59.3^a	39.2
Pellets	11.42^b	81.8^ab	58.2^b	37.8
Pellets + xylanase	11.66^a	84.4^a	58.8^a	39.2
SEM	0.08	0.14	0.38	0.32
Main effect
Feed form
Mash	11.50^b	81.2^b	58.6	38.9
Crumbles	11.58^a	82.8^a	58.8	38.6
Pellets	11.56^a	83.1^a	58.5	38.5
Xylanase
−	11.43^b	81.1^b	58.2^b	38.1
+	11.66^a	83.6^a	59.1^a	39.3
SEM	0.09	0.15	0.38	0.31
P-value
Feed form	0.024	0.011	0.124	0.958
Xylanase	0.037	0.027	0.014	0.943
Feed form × xylanase	0.076	0.098	0.279	0.875

Note: Mean values within a column with different letters differ significantly (P  < .05).

Table 5. Effects of feed form and xylanase enzyme on digestive tract measurements and viscosity of jejunal digesta of heat-stressed broilers fed wheat-based diet (n  = 5).

Treatments	Relative weight (g/100 g BW)			Relative length (cm/100 g BW)
	Proventriculus	Gizzard	Intestine	Duodenum	Jejunum	Ileum	Viscosity (cPs)
Mash	0.51	2.17^a	4.4^a	2.96^a	7.48^a	7.82^a	3.87^a
Mash + xylanase	0.50	2.16^a	4.6^a	2.90^a	7.41^a	7.83^a	2.75^b
Crumble	0.51	1.77^b	4.2^a	2.76^b	7.32^b	7.56^b	3.64^a
Crumble + xylanase	0.52	1.78^b	4.4^a	2.74^b	7.31^b	7.54^b	2.73^b
Pellets	0.52	1.64^c	3.8^b	2.61^c	7.11^c	8.29^c	3.76^a
Pellets + xylanase	0.51	1.65^c	3.6^b	2.62^c	7.09^c	7.31^c	2.72^b
SEM	0.03	0.11	0.11	0.07	0.21	0.22	0.14
Main effect
Feed form
Mash	0.50	2.17^a	4.5^a	2.93^a	7.44^a	7.82^a	3.31
Crumbles	0.51	1.78^b	4.3^a	2.75^b	7.31^b	7.55^b	3.18
Pellets	0.52	1.65^c	3.7^b	2.61^c	7.10^c	7.30^c	3.24
Xylanase
−	0.52	1.86	4.1	2.78	7.30	7.56	3.76^a
+	0.51	1.87	4.2	2.75	7.27	7.57	2.73^b
SEM	0.03	0.11	0.12	0.07	0.21	0.22	0.14
P-value
Feed form	0.322	<0.001	0.002	0.002	0.004	0.002	0.118
Xylanase	0.256	0.236	0.127	0.158	0.148	0.457	0.025
Feed form × xylanase	0.125	0.127	0.098	0.328	0.098	0.328	0.418

Note: Mean values within a column with different letters differ significantly (P  < .05).

Table 6. Effects of feed form and xylanase enzyme on intestinal morphology of heat-stressed broilers fed wheat-based diet (n  = 5).

Treatments	Duodenum			Jejunum			Ileum
	Villus length	Crypt depth	Ratio	Villus length	Crypt depth	Ratio	Villus length	Crypt depth	Ratio
Mash	1310	182	7.19	1174^bc	159^b	7.38^a	809	153	5.29
Mash + xylanase	1312	181	7.25	1170^c	160^ab	7.31^b	814	155	5.25
Crumble	1310	183	7.16	1177^b	161^a	7.31^b	810	153	5.29
Crumble + xylanase	1308	180	7.27	1180^ab	162^a	7.28^c	813	154	5.28
Pellets	1307	182	7.18	1181^a	160^ab	7.38^a	812	153	5.31
Pellets + xylanase	1311	181	7.24	1182^a	162^a	7.30^bc	813	154	5.28
SEM	1.3	0.5	0.04	1.2	1.2	0.06	5.5	1.9	0.07
Main effect
Feed form
Mash	1311	181	7.22	1172^b	159^a	7.37^b	811	154	5.27
Crumbles	1309	182	7.21	1180^a	152^b	7.76^a	812	153	5.29
Pellets	1309	181	7.22	1181^a	153^b	7.72^a	812	154	5.29
Xylanase
−	1309	182	7.18	1177	159	7.36	810	153	5.30
+	1310	181	7.25	1178	160	7.30	813	154	5.27
SEM	1.3	0.5	0.04	1.2	0.2	0.06	5.5	0.2	0.07
P-value
Feed form	0.114	0.184	0.277	0.021	0.017	0.022	0.128	0.178	0.195
Xylanase	0.255	0.224	0.280	0.258	0.158	0.236	0.246	0.182	0.186
Feed form × xylanase	0.263	0.478	0.656	0.318	0.323	0.421	0.235	0.165	0.143

Note: Mean values within a column with different letters differ significantly (P  < .05).