中文摘要：

为了研究芽孢杆菌类益生素对肉鸡血细胞和免疫器官组织结构的影响,本研究选用480羽刚出壳AA肉鸡,随机分对照组、抗生素组、试验Ⅰ和Ⅱ组,对照组饲喂基础日粮,抗生素组添加50mg.kg-1金霉素,试验Ⅰ和Ⅱ组分别添加200和400mg.kg-1富含芽孢杆菌类益生素,试验期42d。结果显示,与对照组相比,试验II组第21和42天肉鸡红细胞数量、嗜碱性粒细胞和单核细胞比例分别显著或极显著增加（P〈0.05或P〈0.01）,第42天胸腺、法氏囊重量和器官指数分别显著增加46.60%和38.23%、66.67%和47.62%（P〈0.05）;试验Ⅰ组第21和42天肉鸡法氏囊重量和器官指数分别显著增加35.40%和36.92%、88.03%和153.97%（P〈0.05）,第42天胸腺重量和器官指数显著增加46.27%和28.13%（P〈0.05）;抗生素组白细胞数量显著减少,第42天脾脏重量和器官指数显著降低（P〈0.05）。试验Ⅰ和Ⅱ组第21和42天肉鸡免疫器官与对照组相比,脾小结数量增多、脾动脉周围淋巴鞘增厚,胸腺皮质增厚、胸腺小体数量减少,法氏囊小结数量增多、小结内淋巴细胞排列紧密,且试验Ⅰ组比试验Ⅱ组更为明显,而抗生素组免疫器官均出现不同程度的发育不良。上述结果表明,添加200mg.kg-1芽孢杆菌益生素比400mg.kg-1更能促进免疫器官的发育,提示芽孢杆菌类益生素具有增强机体免疫功能的作用。

英文摘要：

In order to study the effect of the Bacillus probiotics on blood cells and tissue structure of broilers, 480 newly hatched AA chicken were randomly divided into control group, antibiotic group, experiment Ⅰ and Ⅱ groups. The control group was fed with basal diet, and the antibiotic group was fed with 50 mg·kg-1 chlortetracycline in the basal diet, and the experimental Ⅰ and Ⅱ groups were respectively fed with 200 and 400 mg·kg-1 the Bacillus probiotics in the basal diet for 42 days. The results showed： compared with the control group, the quantity of red cells and the ratio of basophilic granulocytes and monocytes were significantly increased in 21- and 42-day- old broilers （P〈0.05）, and the weight and organ index of thymus and bursal of the 42-day-old broilers were respectively increased by 46.60% and 38.23%, 66.67% and 47.62% （P〈0.05）; The weight and organ index of bursal were significantly increased by 35.40% and 36.92%, 88.03% and 153.97% in the 21- and 42-day-old broilers （P〈0.05）, and the weight and organ index of thymus of the 42-day-old broilers were significantly increased by 46.27% and 28.13% in experiment Ⅰ group （P〈0.05）; the quantity of white cells was obviously decreased, and the weight and organ index of spleen were also obviously decreased in the antibiotic group at the 42 d （P〈0.05）. Compared the tissue structure of immune organs in experiment Ⅰand Ⅱ group with the control group, the quantity of spleen node were increased, and periarterial lymphatic sheath were thickened; the thymic cortex were also thickened, and the quantity of thymic corpuscle were decreased; the bursal node were greatened with tightly rank lymphocytes, and which change were more obvious in the experiment Ⅰthan the experiment Ⅱ group. But the tissue structure of immune organs showed different degree atrophy in the antibiotic group. The results suggested that addition of 200 mg·kg-1 the Bacillus probiotics are better to improve development of immune organs and strengthen immu