Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, USDA, ARS, College Station, TX 77845, USA.
Poult Sci. 2012 Sep;91(9):2235-40. doi: 10.3382/ps.2012-02182.
The present study was aimed at elucidating the effects of supplementing mannan-oligosaccharides (MOS) and probiotic mixture (PM) on growth performance, intestinal histology, and corticosterone concentrations in broilers kept under chronic heat stress (HS). Four hundred fifty 1-d-old chicks were divided into 5 treatment groups and fed a corn-soybean diet ad-libitum. The temperature control (CONT) group was held at the normal ambient temperature. Heat stress broilers were held at 35 ± 2°C from d 1 until the termination of the study at d 42. Heat stress groups consisted of HS-CONT fed the basal diet; HS-MOS fed the basal diet containing 0.5% MOS; HS-PM fed the basal diet containing 0.1% PM; and HS-SYN (synbiotic) fed 0.5% MOS and 0.1% PM in the basal diet. Broilers were examined at d 21 and 42 for BW gain, feed consumption, feed conversion ratio (FCR), serum corticosterone concentrations, and ileal microarchitecture. The results revealed that the CONT group had higher (P < 0.01) feed consumption, BW gain, and lower FCR on d 21 and 42, compared with the HS-CONT group. Among supplemented groups, the HS-MOS had higher (P < 0.05) BW gain and lower FCR compared with the HS-CONT group. On d 21 and 42, the HS-CONT group had higher (P < 0.05) serum corticosterone concentrations compared with the CONT and supplemented groups. The CONT group had higher (P < 0.05) villus height, width, surface area, and crypt depth compared with the HS-CONT group. On d 21, the HS-PM had higher (P < 0.05) villus width and surface area compared with HS-CONT group. On d 42, the HS-SYN had higher (P < 0.05) villus width and crypt depth compared with the HS-CONT group. These results showed that chronic HS reduces broiler production performance, intestinal microarchitecture, and increases adrenal hormone concentrations. Also, supplementation of the MOS prebiotic and the PM can partially lessen these changes.
本研究旨在阐明在慢性热应激（HS）条件下，添加甘露寡糖（MOS）和益生菌混合物（PM）对肉鸡生长性能、肠道组织学和皮质酮浓度的影响。将 450 只 1 日龄雏鸡分为 5 个处理组，自由采食玉米-豆粕日粮。对照组保持在正常环境温度下。从第 1 天到第 42 天研究结束时，热应激组鸡保持在 35±2°C。热应激组包括饲喂基础日粮的 HS-CONT 组；饲喂基础日粮添加 0.5% MOS 的 HS-MOS 组；饲喂基础日粮添加 0.1% PM 的 HS-PM 组；以及在基础日粮中添加 0.5% MOS 和 0.1% PM 的 HS-SYN（合生元）组。在第 21 天和第 42 天，检测了肉鸡的体重增重、饲料消耗、饲料转化率（FCR）、血清皮质酮浓度和回肠微结构。结果表明，与 HS-CONT 组相比，对照组在第 21 天和第 42 天的饲料消耗、体重增重和较低的 FCR 更高（P<0.01）。在添加组中，与 HS-CONT 组相比，HS-MOS 组的体重增重更高（P<0.05），FCR 更低。在第 21 天和第 42 天，HS-CONT 组的血清皮质酮浓度高于 CONT 和添加组（P<0.05）。对照组的绒毛高度、宽度、表面积和隐窝深度高于 HS-CONT 组（P<0.05）。在第 21 天，HS-PM 组的绒毛宽度和表面积高于 HS-CONT 组（P<0.05）。在第 42 天，HS-SYN 组的绒毛宽度和隐窝深度高于 HS-CONT 组（P<0.05）。这些结果表明，慢性 HS 降低了肉鸡的生产性能、肠道微结构，增加了肾上腺激素浓度。此外，MOS 前体和 PM 的添加可以部分减轻这些变化。
