College of Animal Science and Technology, Southwest University, Chongqing 400715, China.
Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907, USA; Department of Animal Hygiene, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.
Poult Sci. 2020 Jan;99(1):142-150. doi: 10.3382/ps/pez571. Epub 2019 Dec 30.
This study examined effect of a dietary synbiotic supplement on the concentrations of plasma thyroid hormones, expressions of heat shock protein 70 (HSP70), and intestinal histomorphology in broiler chickens exposed to cyclic heat stress (HS). Three hundred and sixty day old male Ross 708 broiler chicks were randomly distributed among 3 dietary treatments containing a synbiotic (PoultryStar me) at 0 (control), 0.5 (0.5×), and 1.0 (1.0×) g/kg. Each treatment contained 8 replicates of 15 birds each housed in floor pens in a temperature and lighting controlled room. Heat stimulation was established from days 15 to 42 at 32°C for 9 h daily. The results indicated that under the HS condition, both synbiotic fed groups had lower liver and hypothalamus HSP70 levels (P < 0.001) compared to control group; however, HSP70 mRNA expression was not different among treatments (P > 0.05). There were no treatment effects on the levels of triiodothyronine (T) and thyroxine (T) as well as T/T ratio (P > 0.05). Compared to controls, 1.0× HS broilers had greater villus height in the duodenum (P < 0.01), and greater villus height and villus height:crypt depth ratios in the ileum (P < 0.01). There were no differences among treatments on the measured intestinal parameters in the jejunum (P > 0.05). The results suggest that the synbiotic may ameliorate the negative effects of HS on chicken health as indicated by the changes in the intestinal architecture and the levels of HSP70. Dietary synbiotic supplement could be a feasible nutritive strategy for the poultry industry to improve the health and welfare of chickens when exposed to hot environmental temperature.
本研究探讨了日粮合生素补充剂对暴露于周期性热应激（HS）的肉鸡血浆甲状腺激素浓度、热休克蛋白 70（HSP70）表达和肠道组织形态的影响。将 360 日龄雄性 Ross 708 肉鸡随机分配到 3 种日粮处理组中，日粮中分别添加 0（对照）、0.5（0.5×）和 1.0（1.0×）g/kg 的合生素（PoultryStar me）。每个处理组包含 8 个重复，每个重复 15 只鸡，饲养在温度和光照可控的房间内的地板笼中。从第 15 天到第 42 天，每天进行 9 小时的 32°C 热刺激。结果表明，在 HS 条件下，与对照组相比，两组合生素喂养组的肝脏和下丘脑 HSP70 水平均较低（P<0.001）；然而，处理组之间的 HSP70 mRNA 表达没有差异（P>0.05）。T3 和 T4 水平以及 T/T 比值在各组间均无差异（P>0.05）。与对照组相比，1.0×HS 肉鸡的十二指肠绒毛高度较高（P<0.01），空肠绒毛高度和绒毛高度：隐窝深度比值较高（P<0.01）。各组间在空肠的测量肠道参数无差异（P>0.05）。结果表明，合生素可能通过改变肠道结构和 HSP70 水平来改善 HS 对鸡健康的负面影响。日粮合生素补充剂可能是家禽业在热环境温度下改善鸡健康和福利的可行营养策略。
