Effects of the substitution of oregano essential oil for antibiotics in the plateau-broiler diet

Figures & data

Table 1. Production performance and mortality of plateau broilers among the three groups.

Item	AIW, g	AFW, g	ADG, g	ADFI, g	FCR	Mortality ratio, %	Ascites Mortality, %
NG	892.83 ± 3.19	2108.33 ± 74.34^a	43.41 ± 2.68^a	125.82 ± 4.58^a	2.90 ± 0.10	12.50 ± 6.25^b	10.42 ± 3.61
KG	890.67 ± 8.31	1911.98 ± 72.67^b	36.47 ± 2.68^b	109.00 ± 5.93^b	2.99 ± 0.07	22.92 ± 3.61^a	14.58 ± 3.61
JG	889.17 ± 9.02	2096.50 ± 80.34^a	43.12 ± 3.03^a	123.95 ± 4.54^a	2.87 ± 0.12	10.42 ± 3.61^b	8.33 ± 3.61

NG: group oregano essential oil (basal diets supplemented with oregano essential oil); KG: group control (Basal diets alone); JG: group aureomycin (basal diets supplemented with aureomycin); AIW: average initial body weight；AFW: average final body weight; ADG: average daily gain; ADFI: average daily feed intake; FCR: feed conversion ratio.

Different superscript letters in the same row indicate significant differences (p < 0.05); absent or repeated superscript letters indicate a non-significant difference (p > 0.05).

Table 2. Carcass traits of Partridge Shank chickens among the three groups.

Item	NG	KG	JG
Carcass yield, %	92.40 ± 1.27	91.81 ± 1.28	93.03 ± 1.44
Eviscerated yield with giblet, %	81.33 ± 1.83	79.50 ± 1.87	81.33 ± 1.86
Eviscerated yield, %	66.00 ± 1.55	64.17 ± 1.94	65.33 ± 1.75
Thigh yield, %	10.95 ± 0.19^a	10.17 ± 0.24^b	10.70 ± 0.37^a
Breast yield, %	10.92 ± 0.17^a	10.02 ± 0.26^b	10.65 ± 0.31^a

NG: group oregano essential oil; KG: group control; JG: group aureomycin.

Different superscript letters in the same row indicate significant differences (p < .05); absent or repeated superscript letters indicate a non-significant difference (p > .05).

Figure 1. Dietary nutrient digestibility for plateau broilers of the three groups. NG: group oregano essential oil; KG: group control; JG: group aureomycin; CP: crude protein; EE: ether extract; CA: crude ash; CF: crude fibre.

Table 3. Serum antioxidant indexes for plateau broilers of the three groups.

Item	Units	NG	KG	JG
SOD	U/ml	216.26 ± 28.56^a	143.65 ± 21.31^b	167.70 ± 30.94^b
MDA	nmol/L	4.02 ± 2.02	5.96 ± 0.90	5.012 ± 0.22
T-AOC	U/ml	12.37 ± 0.55	10.37 ± 1.44	11.24 ± 0.04

NG: group oregano essential oil; KG: group control; JG: group aureomycin; T-AOC: total antioxidant capacity; SOD: superoxide dismutase; MDA: malondialdehyde.

Different superscript letters in the same row indicate significant differences (p < .05); absent or repeated superscript letters indicate a non-significant difference (p > .05).

Table 4. Morphological characteristics of the intestines for plateau broilers of the three groups.

Item	NG	KG	JG
Duodenum
VH/μm	1044.12 ± 99.86^a	939.35 ± 85.29^b	956.66 ± 79.88^b
CD/μm	80.47 ± 9.26	74.66 ± 9.03	75.23 ± 5.97
V/C	12.98 ± 1.03	12.58 ± 1.22	12.71 ± 0.98
Jejunum
VH/μm	756.83 ± 52.54^a	587.10 ± 23.54^b	659.3 ± 20.87^ab
CD/μm	77.64 ± 6.35	70.74 ± 4.54	71.43 ± 6.01
V/C	9.75 ± 0.49	8.30 ± 0.85	9.23 ± 0.57
Ileum
VH/μm	683.65 ± 49.56^a	563.90 ± 0.76^b	588.10 ± 1.65^ab
CD/μm	71.19 ± 5.03	67.80 ± 4.42	68.53 ± 4.27
V/C	9.60 ± 0.72	8.32 ± 0.66	8.58 ± 0.79

NG: group oregano essential oil; KG: group control; JG: group aureomycin; VH: villus height; CD: crypt depth; V/C: villus height to crypt depth ratio.

Different superscript letters in the same row indicate significant differences (P<.05); absent or repeated superscript letters indicate a non-significant difference (P>.05).

Figure 2. Intestinal flora. (a) The length distribution of the sequences; (b) rarefaction curve under 97% similarity in all samples. ND: large intestine of the oregano oil group; JD: large intestine of the aureomycin group; KD: large intestine of control group. NX: small intestine of the oregano oil group; JX: small intestine of the aureomycin group; KX: small intestine of the control group; (c) Rank abundance curve of species.

Figure 3. OTU distribution from a Venn plot. ND: large intestine of the oregano oil group; JD: large intestine of the aureomycin group; KD: large intestine of control group. NX: small intestine of the oregano oil group; JX: small intestine of the aureomycin group; KX: small intestine of the control group; OTU: operational taxonomic unit.

Figure 4. Differential taxon among groups based on classification hierarchy tree. ND: large intestine of the oregano oil group; KD: large intestine of control group. NX: small intestine of the oregano oil group; JX: small intestine of the aureomycin group; KX: small intestine of the control group.