Optimal dietary protein level improved growth, disease resistance, intestinal immune and physical barrier function of young grass carp (Ctenopharyngodon idella).
Optimal dietary protein level improved growth, disease resistance, intestinal immune and physical barrier function of young grass carp (Ctenopharyngodon idella).
复制标题
DOI：
10.1016/j.fsi.2016.05.021
复制
发表时间：
2016-08
影响因子：
4.7
通讯作者：
Jing Xu;Pei Wu;Wei‐dan Jiang;Yang Liu;Jun Jiang;S. Kuang;Ling Tang;Wuneng Tang;Yong‐An Zhang-Yong‐
中科院分区：
文献类型：
--
作者：
Jing Xu;Pei Wu;Wei‐dan Jiang;Yang Liu;Jun Jiang;S. Kuang;Ling Tang;Wuneng Tang;Yong‐An Zhang-Yong‐
本试验旨在研究饲料蛋白质对草鱼幼鱼生长、抗病、肠道免疫和物理屏障功能的影响。试验选取540尾草鱼幼鱼（264.11±0.76 g），饲喂6种蛋白质水平分别为143.1、176.7、217.2、257.5、292.2和322.8 g可消化蛋白质kg−1的饲料，为期8周。生长试验结束后，用嗜水气单胞菌攻毒，记录14天的死亡率。结果表明，适宜的饲粮蛋白质水平为：提高了草鱼幼鱼肠道抗菌成分的产生，上调了抗炎因子、κBα抑制剂、雷帕霉素靶蛋白和核糖体蛋白S6激酶1 mRNA水平，下调了促炎因子、核因子κB (NF-κB) P65、NF-κB P52、c-Rel、i -κB激酶β、i -κB激酶γ和eif4e结合蛋白2 mRNA水平（P< 0.05）；提示适宜的饲料蛋白质水平可增强鱼类肠道免疫屏障功能；上调紧密连接复合物、b细胞淋巴瘤蛋白-2、凋亡抑制蛋白、髓细胞白血病-1和nf - e2相关因子2 mRNA水平，上调抗氧化酶活性和mRNA水平，下调肌球蛋白轻链激酶、半胱氨酸天冬氨酸蛋白酶2、3、7、8、9、脂肪酸合成酶配体、凋亡蛋白酶激活因子-1、Bcl-2相关X蛋白、p38丝裂原活化蛋白激酶、幼草鱼3个肠段c-Jun n端蛋白激酶和kelch -样ech相关蛋白1b mRNA水平显著降低（P< 0.05），活性氧、丙二醛和蛋白羰基含量显著降低（P< 0.05），说明适宜的饲料蛋白质水平可改善鱼肠物理屏障功能。最终，对草鱼幼鱼生长性能（PWG）和抗肠炎的最佳饲粮蛋白质水平分别为286.82 g kg - 1 （250.66 g可消化蛋白质kg - 1）和292.10 g kg - 1 （255.47 g可消化蛋白质kg - 1）。
This study investigated the effects of dietary proteins on the growth, disease resistance, intestinal immune and physical barrier functions of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp (264.11 ± 0.76 g) were fed six diets containing graded levels of protein (143.1, 176.7, 217.2, 257.5, 292.2 and 322.8 g digestible protein kg−1diet) for 8 weeks. After the growth trial, fish were challenged withAeromonashydrophilaand mortalities were recorded for 14 days. The results indicated that optimal dietary protein levels: increased the production of antibacterial components, up-regulated anti-inflammatory cytokines, inhibitor of κBα, target of rapamycin and ribosomal protein S6 kinases 1 mRNA levels, whereas down-regulated pro-inflammatory cytokines, nuclear factor kappa B (NF-κB) P65, NF-κB P52, c-Rel, IκB kinase β, IκB kinase γ and eIF4E-binding proteins 2 mRNA levels in three intestinal segments of young grass carp (P< 0.05), suggesting that optimal dietary protein level could enhance fish intestinal immune barrier function; up-regulated the mRNA levels of tight junction complexes, B-cell lymphoma protein-2, inhibitor of apoptosis proteins, myeloid cell leukemia-1 and NF-E2-related factor 2, and increased the activities and mRNA levels of antioxidant enzymes, whereas down-regulated myosin light chain kinase, cysteinyl aspartic acid-protease 2, 3, 7, 8, 9, fatty acid synthetase ligand, apoptotic protease activating factor-1, Bcl-2 associated X protein, p38 mitogen-activated protein kinase, c-Jun N-terminal protein kinase and Kelch-like-ECH-associated protein 1b mRNA levels, and decreased reactive oxygen species, malondialdehyde and protein carbonyl contents in three intestinal segments of young grass carp (P< 0.05), indicating that optimal dietary protein level could improve fish intestinal physical barrier function. Finally, the optimal dietary protein levels for thegrowth performance (PWG)andagainst enteritis morbidityof young grass carp were estimated to be 286.82 g kg−1diet (250.66 g digestible protein kg−1diet) and 292.10 g kg−1diet (255.47 g digestible protein kg−1diet), respectively.