State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Poult Sci. 2012 Mar;91(3):575-82. doi: 10.3382/ps.2010-01293.
We investigated the effect of a 12-d exposure to 34°C plus dietary inclusion of the probiotic Bacillus licheniformis on the egg production, gut morphology, and intestinal mucosal immunity of laying hens. Ninety-six commercial hens (Hy-Line Brown) at the age of 60 wk were randomly allocated to 4 groups. After a period of laying rate adjustment (14 d), all the hens were subjected to 2 temperature treatments (12 d). Birds in 1 group were raised at 21°C and fed a basal diet, and birds in the other 3 groups were raised at 34°C and fed a basal diet supplemented with 0, 10(6), or 10(7) cfu of B. licheniformis per gram of feed, respectively. Rearing at 34°C depressed egg production and feed intake (P < 0.05). Compared with birds kept at 21°C, birds kept at 34°C had elevated serum levels of tumor necrosis factor-α (d 6), IL-1 (d 6 and 12), and corticosterone (d 6); decreased villus height (ileum: d 6; cecum: d 6 and 12) and ratio of villus height to crypt depth (ileum: d 6; cecum: d 6 and 12); fewer intraepithelial lymphocytes (ileum: d 6; cecum: d 6) and IgA-secreting cells (ileum: d 6; cecum: d 6 and 12); and more mast cells (ileum: d 6; cecum: d 6 and 12; P < 0.05). The number of goblet cells in the cecum increased at d 6 in heat-treated birds, and then deceased at d 12 (P < 0.05). Moreover, morphological examination showed injury to the villi of birds kept at 34°C. In general, inclusion of 10(7) cfu/g of B. licheniformis in the diet of heat-stressed hens was effective in overcoming the observed decline in egg production and feed intake, restoring the impaired villus structure, and sustaining a balanced mucosal immune response. Therefore, the probiotic B. licheniformis may be useful for ameliorating the adverse influence of heat on the egg production and gut health of laying hens.
我们研究了 12 天 34°C 暴露和膳食添加益生菌地衣芽孢杆菌对产蛋鸡产蛋性能、肠道形态和肠道黏膜免疫的影响。60 周龄的 96 只商业母鸡（海兰褐）随机分为 4 组。经过一段时间的产蛋率调整（14 天）后，所有母鸡都接受了 2 种温度处理（12 天）。一组鸡在 21°C 下饲养，饲喂基础日粮，另外 3 组鸡在 34°C 下饲养，基础日粮中分别添加 0、10(6)或 10(7)cfu/g 的地衣芽孢杆菌。在 34°C 下饲养会降低产蛋率和采食量（P<0.05）。与在 21°C 下饲养的鸡相比，在 34°C 下饲养的鸡血清肿瘤坏死因子-α（第 6 天）、白细胞介素-1（第 6 天和第 12 天）和皮质酮（第 6 天）水平升高；空肠（第 6 天）和盲肠（第 6 天和第 12 天）的绒毛高度和隐窝深度比值降低；空肠（第 6 天）和盲肠（第 6 天和第 12 天）的上皮内淋巴细胞和 IgA 分泌细胞减少；空肠（第 6 天）和盲肠（第 6 天和第 12 天）的肥大细胞增多（P<0.05）。在热处理鸡中，盲肠的杯状细胞数量在第 6 天增加，然后在第 12 天减少（P<0.05）。此外，形态学检查显示 34°C 下饲养的鸡的绒毛受损。一般来说，在热应激母鸡的日粮中添加 10(7)cfu/g 的地衣芽孢杆菌可有效克服产蛋率和采食量下降，恢复受损的绒毛结构，并维持黏膜免疫反应的平衡。因此，益生菌地衣芽孢杆菌可能有助于减轻热应激对产蛋鸡产蛋性能和肠道健康的不利影响。
