Effects of gallus epidermal growth factor（gEGF）from chicken embryos on growth performance, serum biochemical indices, immune function and intestinal morphology of broilers

Figures & data

Table 1. Composition and nutrient levels of the basal diet (air-dry basis).

Items	Starter (1 to 21 day)	Grower (22 to 42 day)
Ingredients, %
Corn	55.00	60.00
Soybean meal	34.00	29.00
Fish meal	4.00	3.00
Soybean oil	3.00	4.00
Lysine	0.20	0.25
Methionine	0.25	0.20
Threonine	0.05	1.30
Dicalcium phosphate	1.50	1.00
Limestone	1.00	0.25
Premix^1	1.00	1.00
Total	100.00	100.00
ME^2, Mcal/kg	3.00	3.10
Crude protein, %	22.00	20.00
Calcium, %	1.00	0.90
Available phosphorus, %	0.67	0.65
Methionine, %	0.60	0.50
Lysine, %	1.30	1.25
Methionine + Cystine, %	0.93	0.80
Threonine, %	0.86	0.76

¹Premix provided the following per kilogram of diet: vitamin A, 6000 IU; vitamin D3, 3000 IU; vitamin E, 30 IU; vitamin B1, 3 mg; vitamin B12, 1 mg; vitamin B2, 6 mg; vitamin K, 2 mg; vitamin B6, 2.5 mg; choline chloride, 1 mg; biotin, 0.2 mg; folic acid, 1 mg; niacin, 30 mg; pantothenic acid, 15 mg; lysine, 2 mg; methionine, 0.5 mg; threonine, 0.8 mg; NaCl, 2.5 mg; Fe, 60 mg; Zn, 70 mg; Mn, 80 mg; Cu, 6 mg; I, 1.1 mg; Se, 0.3 mg.

²ME based on calculated values; others were analysed values.

Figure 1. Changes of gEGF concentration after digestion with artificial gastric juice and artificial intestinal juice. (a) artificial gastric juice. (b) artificial intestinal juice. values are mean ± SEM. n = 3. a–b–c Means with different superscripts in the same row indicate significantly difference (p < .05). Abbreviations: gEGF: gallus epidermal growth factor; SEM: Standard error of means.

Table 2. Effect of dietary gEGF on the growth performance of broilers.

		gEGF, ng/kg					p-value
Item	Control	4	6	8	12	SEM	Anova	Linear	Quadratic	Cubic
Starter (day 1 to 21)
ADG, (g/d)	43.64^b	47.70^a	47.09^a	45.43^ab	48.80^a	1.13	<.01	<.01	.43	<.01
ADFI, (g/d)	62.08^b	67.44^a	67.29^a	62.22^b	62.80^b	1.79	.01	.36	<.01	.01
FCR	1.48	1.43	1.44	1.34	1.35	0.06	.10	.01	.95	.72
Grower (day 22 to 42)
ADG, (g/d)	72.32	78.94	72.27	72.38	71.00	2.79	.06	.15	.22	.07
ADFI, (g/d)	130.26^b	148.26^a	139.69^ab	139.83^ab	131.87^b	5.47	.02	.67	<.01	.14
FCR	1.81	1.88	1.94	1.93	1.86	0.07	.32	.33	.06	.70
Overall (Day 1 to 42)
ADG, (g/d)	58.72^b	63.31^a	59.85^ab	58.48^b	59.34^ab	1.43	.02	.27	.17	<.01
ADFI, (g/d)	101.47^b	115.31^a	105.11^b	103.69^b	104.10^b	2.99	<.01	.35	.03	<.01
FCR	1.73	1.82	1.76	1.77	1.75	0.05	.46	.97	.28	.30

^a–bMeans with different superscripts in the same row indicate significant differences (p< .05) & (p < .01). Abbreviations: ADG: average daily gain; ADFI: average daily feed intake; FCR: feed conversion ratio; gEGF: gallus epidermal growth factor.

Table 3. Effect of dietary gEGF on the serum biochemical indices of broilers.

Item	Control	gEGF, ng/kg				SEM	p-value
		4	6	8	12		Anova	Linear	Quadratic	Cubic
TP, g/L	38.97	30.89	38.07	40.25	35.46	5.01	.38	.84	.91	.06
ALB, g/L	11.34	11.58	12.17	11.11	12.63	0.69	.29	.23	.65	.20
GPT, lU/L	13.98	13.90	14.09	7.37	9.78	3.47	.23	.07	.84	.27
GOT, IU/L	37.66	42.67	44.17	41.93	34.09	5.89	.44	.56	.08	.88
UA, umol/L	64.32	80.18	75.77	111.01	98.68	24.87	.37	.09	.80	.63
GLU, mmol/L	10.00	9.24	9.81	10.29	10.20	0.93	.81	.50	.63	.38
DAO, U/L	58.75^a	54.65^a	46.75^a	29.33^b	45.75^a	4.43	<.01	<.01	.02	<.01

^a–bMeans with different superscripts in the same row indicate significant differences (p< .05) & (p < .01). Abbreviations: TP: total protein; ALB: albumen; GPT: glutamic pyruvic transaminase; GOT: glutamic oxalacetic transaminase; UA: uric acid; GLU: glucose; DAO: diamine oxidase; gEGF: gallus epidermal growth factor; ME: Metabolizable energy.

Table 4. Effect of dietary gEGF on serum antioxidant capacity of broilers.

Item	Control	gEGF, ng/kg				SEM	p-value
		4	6	8	12		Anova	Linear	Quadratic	Cubic
CAT, U/ml	7.77^b	14.55^a	14.86^a	10.07^ab	10.88^ab	1.66	<.01	.65	<.01	<.01
T-SOD, U/ml	156.89	173.77	174.49	182.46	174.98	7.98	.07	.02	.07	.97
T-AOC, U/ml	3.82^b	6.62^ab	4.11^b	5.96^ab	8.61^a	0.93	<.01	<.01	.13	.02
GSH-PX, U	1214.82^b	1196.30^b	1400.00^ab	1477.78^a	1507.41^a	75.99	<.01	<.01	.89	.13
MDA, nmol/ml	4.05^a	3.78^ab	3.79^ab	3.46^ab	3.15^b	0.38	.03	<.01	.54	.65

^a–bMeans with different superscripts in the same row indicate significant differences (p< .05) & (p< .01). Abbreviations: CAT: catalase; T-SOD: total superoxide dismutase; MDA: malondialdehyde; GSH-PX: glutathione peroxidase; T-AOC: total antioxidant capacity; control: basic diet; SEM: standard error of means; gEGF: gallus epidermal growth factor.

Table 5. Effect of dietary gEGF on the index of immune organs of broilers.

Item	Control	gEGF, ng/kg				SEM	p-value
		4	6	8	12		Anova	Linear	Quadratic	Cubic
Index of thymus, %	0.31^b	0.34^ab	0.35^ab	0.44^a	0.36^ab	0.42	.03	.03	.20	.14
Index of spleen, %	0.10	0.11	0.10	0.13	0.09	0.02	.28	.67	.26	.16
Index of BF, %	0.11^b	0.16^a	0.15^a	0.17^a	0.14^ab	0.01	<.01	.03	<.01	.94

^a–bMeans with different superscripts in the same row indicate significant differences (p < .05) & (p < .01). Abbreviations: BF: bursa of Fabricius. Index of immune organ = weight of the immune organ (g)/body weight (g). Control: basic diet; SEM: Standard error of means; gEGF: gallus epidermal growth factor.

Table 6. Effect of dietary gEGF on serum immunoglobulins of broilers.

		gEGF, ng/kg					p-value
Item	Control	4	6	8	12	SEM	Anova	Linear	Quadratic	Cubic
IgA, ug/mL	259.68^b	339.21^ab	357.00^ab	466.71^a	347.21^ab	62.38	<.05	.04	.08	.24
IgM, ug/mL	775.33^b	848.53^ab	892.49^ab	1206.99^a	868.01^ab	132.51	.03	.08	.13	<.05
IgG, ug/mL	2967.20	3232.36	3156.52	3347.58	2544.56	520.62	.58	.54	.19	.58

^a–bMeans with different superscripts in the same row indicate significant differences (p < .05) & (p < .01). IgA: Immunoglobulin A; IgM: Immunoglobulin M; IgG: Immunoglobulin G; SEM: Standard error of means; gEGF: gallus epidermal growth factor.

Table 7. Effect of dietary gEGF on mucosal morphological traits of small intestine of broilers.

Item	Control	gEGF, ng/kg				SEM	p-value
		4	6	8	12		Anova	Linear	Quadratic	Cubic
Duodenum
VH, um	1513.90^ab	1539.79^a	1491.74^ab	1519.50^ab	1411.53^b	42.82	.04	.02	.10	.52
CD, um	150.46^a	144.54^ab	125.54^bc	117.82^c	136.29^abc	8.59	<.01	<.01	<.01	<.05
VH/CD	10.12^b	10.89^ab	11.73^ab	13.08^a	11.15^ab	0.80	<.01	.02	.02	.07
Jejunum
VH, um	1246.93^d	1768.95^b	1299.37^d	1923.78^a	1515.28^c	44.31	<.01	<.01	<.01	.68
CD, um	157.46^a	153.29^ab	127.77^bc	109.03^c	149.90^ab	8.80	<.01	<.01	<.01	<.01
VH/CD	9.17^b	11.60^ab	10.54^b	13.78^a	10.60^b	1.06	<.01	.04	.02	.23
Ileum
VH, um	1137.14	1094.34	1088.71	1203.16	1147.52	54.94	.25	.30	.52	.10
CD, um	157.03^a	98.78^b	98.39^b	126.00^ab	107.62^b	12.65	<.01	.02	<.01	<.01
VH/CD	8.61^b	9.54^ab	9.11^ab	10.61^a	9.66^ab	0.57	.02	.02	.22	.38

^a–cMeans with different superscripts in the same row indicate significant differences (p < .05) & (p < .01). Abbreviations: VH: villus height; CD: crypt depth; VH/CD: the ratio of villus height to crypt depth. Control: basic diet; SEM: Standard error of means; gEGF: gallus epidermal growth factor.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.