益生枯草芽胞杆菌HDRaBS1缓解蛋鸡热应激效果
Effects of Bacillus subtilis HDRaBS1 on alleviating heat stress of laying hens

选取868只280日龄产蛋率相近海兰褐蛋鸡，随机分为高温组（33℃）、益生菌组（枯草芽胞杆菌+33℃）、室温组（26 ℃），试验期为20 d，研究益生枯草芽胞杆菌HDRaBS1缓解动物热应激的可行性及其机制。结果发现，与高温组相比，益生菌组在全期产蛋率、平均日采食量、平均蛋质量方面分别提高了2.60%（P<0.05）、2.91%（P>0.05）和0.96%（P>0.05），但没有达到室温组水平，且在腹泻率、蛋破损率方面均有降低；血清内毒素、IL-1水平分别降低了37.41%（P>0.05）和20.98%（P<0.05），IL-10含量提高了41.05%（P>0.05）；益生菌显著上调盲肠紧密连接基因occludin、ZO-1和JAM-A mRNA的表达（P<0.05），上调肠黏膜修复基因EGF mRNA的表达（P<0.05），显著提高肠绒毛高度，而隐窝深度之间无显著差异(P>0.05)。因此，添加枯草芽胞杆菌HDRaBS1能有效缓解蛋鸡热应激症状。
Eight hundred sixty eight Hy-Line Brown laying hens about 280 d old with similar egg production rate,were randomly divided into high temperature group (33℃),probiotics group (Bacillus subtilis+33℃) and room temperature group (26℃).The experiment was conducted for 20 d to investigate the feasibility and mechanism of B. subtilis HDRaBS1 on alleviating animal heat stress.The results showed that the egg production rate,average daily feed intake and average egg weight of the probiotics group increased by 2.60% (P<0.05),2.91% (P>0.05) and 0.96% (P>0.05),respectively,compared with the high temperature group,but were less than those of the room temperature group.In addition,the diarrhea rate and broken egg ratio of the probiotics group were reduced,serum endotoxin and IL-1were reduced by 37.41% (P>0.05) and 20.98% (P<0.05),while IL-10 expression was increased by 41.05% (P>0.05) than those of the high temperature group.Moreover,in the probiotics group,the mRNA expression of many genes in the cecum,including the tight junction occludin,ZO-1 and JAM-A,and the mucosa repair gene of EGF were significantly up-regulated (P<0.05),intestinal villus height (P<0.05) was improved,while no pronounced variation of the crypt depth was observed (P>0.05).Therefore,adding B.subtilis HDRaBS1 could effectively alleviate the symptoms of heat stress-induced laying hens.