关键词：
Bacillus subtilis;intestinal barrier;laying hen;montmorillonite;oxidation status
摘要：
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 x 2 factorial arrangement of treatments (n = 6) for 10 wk as follows: (1) basal diet; (2) the basal diet plus 5 x 10(8) cfu BS/kg; (3) the basal diet plus 0.5 g MMT/kg; and (4) the basal diet plus 5 x 10(8) 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-kappaB 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.
摘要：
This study was conducted to investigate the effects of dietary supplementation with montmorillonite (MMT) on performance, intestinal endotoxin concentration, gut mucosal oxidation status, intestinal morphology and permeability, and immunological barrier function of laying hens during late production. Four hundred and eighty 75-week-old laying hens (Lohmann Brown) were randomly assigned to five treatments with eight replicates per treatment and 12 hens in each replicate. The hens were fed the basal diet supplemented with 0 (control), 0.3, 0.6, 0.9, or 1.2 g MMT/kg for 70 days. Compared with the control, supplemented with 0.9 g MMT/kg increased egg mass significantly (p < 0.05) during weeks 1-5 of the experiment. Supplemented with 0.6 and 0.9 g MMT/kg also increased the endotoxin concentration in the ileal digesta (p < 0.05), but decreased the MDA concentration in the ileum significantly (p < 0.05). The T-AOC in the jejunum of the group fed 0.3 g MMT/kg was significantly increased (p < 0.05). Compared with the control, the villus height:crypt depth of ileum from the groups fed 0.6, 0.9, and 1.2 g MMT/kg increased significantly (p < 0.05). The sIgA concentration of jejunum in the groups fed 0.6 and 0.9 g MMT/kg was higher ( p < 0.05) than the control. The MMT supplementation linearly increased (p < 0.05) the mRNA expression of claudin-1 and claudin-5 in the jejunum. Dietary MMT supplementation down-regulated the mRNA expression of NF-kappa B P65 and TNF-alpha in the jejunum in a linear and quadratic manner (p < 0.05). The IL-1 beta mRNA expression of jejunum in the group fed 0.6 g MMT/kg was lower ( p < 0.05) than the control. In conclusion, dietary supplementation with MMT may improve the gut barrier functions and suggests that 0.9 g/kg of MMT in diets may be the optimal supplemental level for laying hens in late production.
摘要：
<jats:title>Abstract</jats:title><jats:p>To investigate the supplemental effects of <jats:italic>Bacillus subtilis</jats:italic> C‐3102 on the production, hatching performance, egg quality, serum antioxidant capacity and immune response of laying breeders, a total of 480 Xuefeng black‐bone (25‐week‐old) hens were randomly assigned into four treatment groups: Hens fed the basal diets with 0 (CON), 3.0×10<jats:sup>5</jats:sup> (BS‐1), 6.0×10<jats:sup>5</jats:sup>cfu/g (BS‐2) and 9.0×10<jats:sup>5</jats:sup> (BS‐3) cfu/g of <jats:italic>B</jats:italic>.<jats:italic>subtilis</jats:italic> C‐3102. As the <jats:italic>B</jats:italic>.<jats:italic>subtilis</jats:italic> C‐3102 level increased, egg weight (linear, <jats:italic>p</jats:italic><0.01; quadratic, <jats:italic>p</jats:italic>=0.003), fertility (linear, <jats:italic>p</jats:italic>=0.021; quadratic, <jats:italic>p</jats:italic>=0.059), hatchability (linear, <jats:italic>p</jats:italic>=0.038; quadratic, <jats:italic>p</jats:italic>=0.119) and yolk colour (linear, <jats:italic>p</jats:italic>=0.006; quadratic, <jats:italic>p</jats:italic>=0.021) increased in a linear or quadratic manner. Yolk index increased quadratically (linear, <jats:italic>p</jats:italic>=0.054; quadratic, <jats:italic>p</jats:italic>=0.017), and eggshell thickness (linear, <jats:italic>p</jats:italic>=0.036; quadratic, <jats:italic>p</jats:italic>=0.128), the activity of GSH‐Px (linear, <jats:italic>p</jats:italic>=0.024; quadratic, <jats:italic>p</jats:italic>=0.078), the concentration of IgM (linear, <jats:italic>p</jats:italic>=0.016; quadratic, <jats:italic>p</jats:italic>=0.056) and the level of AIV‐Ab (linear, <jats:italic>p</jats:italic>=0.034; quadratic, <jats:italic>p</jats:italic>=0.103) in the serum increased linearly as dietary supplementation of <jats:italic>B.subtilis</jats:italic> C‐3102 increased. The results showed that dietary treatments did not affect egg production, feed conversion ratio, egg mass, hatchability of fertile eggs, eggshell‐breaking strength, egg‐shape index, yolk percentage, Haugh unit, T‐SOD, T‐AOC, MDA, IgA and IgG concentrations and the level of NDV‐Ab in the serum. In conclusion, dietary supplementation of 9.0×10<jats:sup>5</jats:sup>cfu/g <jats:italic>B.subtilis</jats:italic> C‐3102 in laying breeders diets may be a feasible means of effectively increasing egg weight, fertility and hatchability, and improving egg quality such as eggshell thickness, yolk index and yolk colour. Besides, <jats:italic>B.subtilis</jats:italic> C‐3102 can enhance the activity of GSH‐Px, the concentration of IgM and the level of AIV‐Ab in the serum.</jats:p>
