This study was conducted to evaluate the effects and combinational effects of Bacillus subtilis (BS) and montmorillonite (MMT) on laying performance, gut mucosal oxidation status, and intestinal immunological and physical barrier functions of laying hens. Three hundred sixty laying hens (29-week-old) were randomly assigned to a 2 × 2 factorial arrangement of treatments (n = 6) for 10 wk as follows: (1) basal diet; (2) the basal diet plus 5 × 108 cfu BS/kg; (3) the basal diet plus 0.5 g MMT/kg; and (4) the basal diet plus 5 × 108 cfu BS/kg and 0.5 g MMT/kg. Dietary supplementation with BS increased egg production and egg mass, the activities of catalase (CAT) and total superoxide dismutase in the intestinal mucosa, and villus height and villus height-to-crypt depth ratio of the jejunum (P < 0.05) but downregulated the mRNA expression levels of toll-like receptor 4 and myeloid differentiation factor 88 (MyD88) in the duodenum and jejunum, interleukin 1 beta in the duodenum, and nuclear factor kappa B P65 (NF-κB P65) and tumor necrosis factor alpha in the jejunum (P < 0.05). Dietary supplementation with MMT increased egg production and egg mass, the concentration of secretory immunoglobulin A in the duodenum, and the occludin mRNA expression level in the jejunum (P < 0.05) but reduced feed conversion ratio, malondialdehyde concentration in the duodenum and jejunum, and the mRNA expression level of MyD88 in the jejunum (P < 0.05). In addition, there was an interaction effect between BS and MMT supplementation on the CAT activity and the MyD88 mRNA expression level in the duodenum and the mRNA expression level of occludin in the jejunum (P < 0.05). In conclusion, dietary BS and MMT and their combination may improve the intestinal health status of laying hens, which may contribute to the increase in hens' laying performance.

中文翻译：

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枯草芽孢杆菌和蒙脱石对蛋鸡肠道健康状况的影响及其联合作用。

进行这项研究以评估枯草芽孢杆菌（BS）和蒙脱土（MMT）对蛋鸡产蛋性能，肠道粘膜氧化状态以及肠道免疫和物理屏障功能的影响及其联合作用。将三百六十只产蛋母鸡（29周龄）随机分配至2×2阶乘处理（n = 6），每周10周，方法如下：（1）基础饮食；（2）基础饮食加5×108 cfu BS / kg；（3）基础饮食加0.5 g MMT / kg；（4）基础饮食加5×108 cfu BS / kg和0.5 g MMT / kg。日粮中添加BS可以提高产蛋量和蛋重，肠粘膜中过氧化氢酶（CAT）的活性和总超氧化物歧化酶的活性，以及​​空肠的绒毛高度和绒毛高度与隐窝深度之比（P <0。05），但下调十二指肠和空肠中Toll样受体4和髓样分化因子88（MyD88）的mRNA表达水平，十二指肠中白介素1 beta的表达，以及核因子κBP65（NF-κBP65）和肿瘤坏死空肠中的α因子（P <0.05）。日粮中添加MMT可以增加产蛋量和蛋重，十二指肠中分泌型免疫球蛋白A的浓度以及空肠中occludin mRNA的表达水平（P <0.05），但饲料转化率降低，十二指肠和空肠中的丙二醛浓度降低，以及空肠中MyD88的mRNA表达水平（P <0.05）。此外，补充BS和MMT对CAT活性，十二指肠MyD88 mRNA表达水平和空肠中occludin mRNA表达水平均具有交互作用（P <0.05）。总之，日粮BS和MMT及其组合可改善蛋鸡的肠道健康状况，这可能有助于提高蛋鸡的产蛋性能。