College of Animal Sciences, Zhejiang University, Hangzhou, China.
College of Animal Sciences, Zhejiang University, Hangzhou, China.
Poult Sci. 2020 Dec;99(12):6307-6316. doi: 10.1016/j.psj.2020.09.026. Epub 2020 Sep 18.
In the present study, we evaluated the effects of various stocking densities on the tracheal barrier and plasma metabolic profiles of finishing broilers. We randomly assigned 1,440 Lingnan Yellow feathered broilers (age 22 d) to 5 different stocking density groups (8 m, 10 m, 12 m, 14 m, and 16 m). Each of these consisted of 3 replicates. The interleukin (IL)-1β and IL-10 concentrations were substantially higher in the 16 m treatment group than they were in the 8 m and 10 m treatment groups (P < 0.05). Nevertheless, IL-4 did not significantly differ among the 5 treatments (P > 0.05). The tracheal mucosae of the birds in the 16 m group (high stocking density, HSD) were considerably thicker than those for the birds in the 10 m group (control, CSD). Relative to CSD, the claudin1 expression level was lower, and the muc2 and caspase3 expression levels were higher for HSD. Compared with CSD, 10 metabolites were significantly upregulated (P < 0.05), and 7 were significantly downregulated (P < 0.05) in HSD. Most of these putative diagnostic biomarkers were implicated in matter biosynthesis and energy metabolism. A metabolic pathway analysis revealed that the most relevant and critical biomarkers were pentose and glucuronate interconversions and the pentose phosphate pathway. Activation of the aforementioned pathways may partially counteract the adverse effects of the stress induced by high stocking density. This work helped improve our understanding of the harmful effects of high stocking density on the tracheal barrier and identified 2 metabolic pathways that might be associated with high stocking density-induced metabolic disorders in broilers.
在本研究中，我们评估了不同饲养密度对育肥肉鸡气管屏障和血浆代谢谱的影响。我们将 1440 只岭南黄羽肉鸡（22 日龄）随机分为 5 个不同饲养密度组（8、10、12、14 和 16 m），每组 3 个重复。结果发现，16 m 组的白细胞介素（IL）-1β和 IL-10 浓度明显高于 8 m 和 10 m 组（P<0.05），但 5 种处理方式之间的 IL-4 没有显著差异（P>0.05）。16 m 组（高密度饲养，HSD）的气管黏膜明显比 10 m 组（对照，CSD）厚。与 CSD 相比，HSD 的 Claudin1 表达水平较低，Muc2 和 Caspase3 表达水平较高。与 CSD 相比，HSD 中有 10 种代谢物显著上调（P<0.05），7 种代谢物显著下调（P<0.05）。这些潜在的诊断生物标志物大多与物质生物合成和能量代谢有关。代谢途径分析显示，最相关和关键的生物标志物是戊糖和葡萄糖醛酸的相互转化以及戊糖磷酸途径。上述途径的激活可能部分抵消了高密度饲养引起的应激的不利影响。这项工作有助于我们更好地了解高密度饲养对气管屏障的有害影响，并确定了 2 个可能与肉鸡高密度饲养引起的代谢紊乱相关的代谢途径。
