Lin Yang, Olukosi Oluyinka A
Department of Poultry Science, University of Georgia, Athens, GA 30602, USA.
Animals (Basel). 2021 Sep 15;11(9):2698. doi: 10.3390/ani11092698.
Two 21-day experiments were conducted to investigate the effects of exogenous enzymes on growth performance, tight junctions, and nutrient transporters, jejunal oligosaccharides and cecal short-chain fatty acids (SCFA) of broiler chickens challenged with mixed . Two different basal diets: high fiber-adequate protein (HFAP; Expt. 1) or low fiber-low protein (LFLP; Expt. 2) were used in the two experiments. In each experiment, birds were allocated to four treatments in a 2 × 2 factorial arrangement (with or without protease and xylanase combination; with or without challenge). In Expt. 1, with HFAP diets, upregulated ( < 0.05) the expression of claudin-1, but downregulated ( < 0.05) glucose transporters GLUT2/GLUT5. On the contrary, enzymes downregulated ( < 0.05) claudin-1 and alleviated the -depressed GLUT2/GLUT5 expression. In both experiments, decreased ( < 0.05) cecal saccharolytic SCFA and increased ( < 0.05) cecal branched-chain fatty acids. The challenge × enzyme interaction ( < 0.05) showed that enzymes reversed the effects on fermentation pattern shift. In conclusion, altered tight junctions and nutrient transporters expression promoted cecal proteolytic fermentation and inhibited saccharolytic fermentation. Exogenous enzymes showed the potential of alleviating the -induced intestinal gene expression changes and reversing the unfavorable cecal fermentation pattern.
进行了两项为期21天的试验，以研究外源酶对受到混合应激的肉鸡生长性能、紧密连接、营养转运蛋白、空肠寡糖和盲肠短链脂肪酸（SCFA）的影响。两项试验采用了两种不同的基础日粮：高纤维-适宜蛋白（HFAP；试验1）或低纤维-低蛋白（LFLP；试验2）。在每项试验中，将鸡只按2×2析因设计分为四种处理（添加或不添加蛋白酶和木聚糖酶组合；添加或不添加应激）。在试验1中，对于HFAP日粮，应激上调（P<0.0）claudin-1的表达，但下调（P<0.05）葡萄糖转运蛋白GLUT2/GLUT5。相反，酶下调（P<0.05）claudin-1并缓解应激导致的GLUT2/GLUT5表达降低。在两项试验中，应激均降低（P<0.05）盲肠的糖分解SCFA并增加（P<0.05）盲肠的支链脂肪酸。应激×酶的交互作用（P<0.05）表明，酶可逆转应激对发酵模式转变的影响。总之，应激改变紧密连接和营养转运蛋白的表达，促进盲肠蛋白水解发酵并抑制糖分解发酵。外源酶显示出缓解应激诱导的肠道基因表达变化以及逆转不利的盲肠发酵模式的潜力。
