Sixty-week-old Hy-Line brown laying hens were randomly divided into five groups and fed different diets over a period of 84 days. Experimental treatments included a basal diet (control); the basal diet supplemented with 1.0 × 10⁶B. licheniformis yb-214245; the basal diet supplemented with 1.0 × 10⁶B. subtilis yb-114246; a combination of both strains in a 2:1 ratio (6.6 × 10⁵:3.3 × 10⁵B. licheniformis yb-214245:B. subtilis yb-114246); and the latter, added with 5 mg/kg flavomycin. Basal diet supplementation with the combined Bacillus species improved egg-laying performance in aging hens significantly (P < 0.05). Eggshell strength improved significantly with this treatment, compared to the control or the antibiotic-supplemented groups (P < 0.05). The levels of total cholesterol, triglycerides, and very low-density lipoprotein cholesterol in egg yolk declined significantly more in the Bacillus-treated group than in the control or the antibiotic-supplemented groups (P < 0.01). Small intestinal morphology was better in the hens treated with the Bacillus combination than in the hens in the control group (P < 0.05). The total number of aerobic bacteria (Bacillus, Lactobacillus, and Bifidobacterium) in the cecum was significantly higher in all the Bacillus-supplemented hens than either in the control or the antibiotic-supplemented hens (P < 0.01); additionally, the number of E. coli and Salmonella was significantly lower than in the control group (P < 0.01). In conclusion, diet supplementation with the combination of Bacillus species used here for aging laying hens improved their growth performance, cecal bacterial composition, egg quality, and small intestine morphology.

中文翻译：

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两种芽孢杆菌的组合使用对衰老蛋鸡生产性能，蛋品质，小肠粘膜形态和盲肠微生物群谱的影响。

将60周龄的Hy-Line棕色产蛋母鸡随机分为五组，并在84天内饲喂不同的日粮。实验治疗包括基础饮食（对照）；基础饮食，辅以1.0×10 ⁶ B. licheniformis yb-2 14245；基础饮食，补充1.0×10 ⁶ B. subtilis yb-1 14246；两种菌株的组合比例为2：1（6.6×10 ⁵：3.3×10 ⁵ B.地衣芽孢杆菌yb-2 14245：枯草芽孢杆菌yb-1 14246）; 后者加入5 mg / kg黄霉素。基础饮食与芽孢杆菌种类的组合可显着改善衰老母鸡的产卵性能（P <0.05）。与对照组或补充抗生素的组相比，这种处理的蛋壳强度显着提高（P  <0.05）。芽孢杆菌治疗组的蛋黄中总胆固醇，甘油三酸酯和极低密度脂蛋白胆固醇的水平下降幅度明显大于对照组或补充抗生素的组（P  <0.01）。Bacillus组合治疗的母鸡的小肠形态要好于对照组（P  <0.05）。有氧细菌的总数（芽孢杆菌，乳杆菌和双歧杆菌）在所有补充芽孢杆菌的母鸡中盲肠中的盲肠均显着高于对照或补充抗生素的母鸡中的盲肠（P  <0.01）; 此外，大肠杆菌和沙门氏菌的数量明显低于对照组（P  <0.01）。总而言之，在这里使用的芽孢杆菌种类的饮食补充饲料可以改善它们的生长性能，盲肠细菌组成，鸡蛋质量和小肠形态。