The present study evaluated the effect of cinnamaldehyde (CIN) on the growth performance and digestion and absorption capacity of grass carp (Ctenopharyngodon idella). Fish were fed five diets including graded levels of CIN for 60 days. The results indicated that (1) appropriate CIN supplementation increased the growth performance and promoted the intestine growth of grass carp; (2) dietary appropriate CIN supplementation increased the digestion and absorption capacity by increasing the activities of intestinal and hepatopancreas digestive enzymes (lipase, chymotrypsin, trypsin, and amylase) and intestinal brush border enzymes (creatine kinase (CK), Na+/K+-ATPase, γ-glutamyl transpeptidase (γ-GT), and alkaline phosphatase (AKP)); (3) dietary CIN increased the absorption capacity which may be associated with the upregulated messenger RNA (mRNA) abundances of their amino acid transporters (AATs) in the intestine, which might be associated with activating the target of rapamycin (TOR) signaling pathway. The best CIN supplementation in the diets of grass carp was estimated to be 76.40 mg kg-1 diet based on the best percent weight gain (PWG). In general, CIN increased the digestion and absorption capacity of grass carp and raised the mRNA abundances of AATs which may be partly related to activation of the TOR signaling pathway.

中文翻译：

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肉桂醛可改善草鱼（Ctenopharyngodon idella）的生长性能以及消化吸收能力。

本研究评估了肉桂醛（CIN）对草鱼（Ctenopharyngodon idella）的生长性能以及消化吸收能力的影响。为鱼类喂食五种日粮，包括60天内的CIN分级水平。结果表明：（1）适当补充CIN可以提高草鱼的生长性能，促进草鱼肠的生长。（2）饮食中适当的CIN补充通过增加肠和肝胰消化酶（脂肪酶，胰凝乳蛋白酶，胰蛋白酶和淀粉酶）和肠刷缘酶（肌酸激酶（CK），Na + / K + -ATPase）的活性来增强消化吸收能力，γ-谷氨酰转肽酶（γ-GT）和碱性磷酸酶（AKP））；（3）日粮CIN增加了其吸收能力，这可能与其肠中氨基酸转运蛋白（AAT）的信使RNA（mRNA）丰度上调有关，这可能与激活雷帕霉素（TOR）信号通路的靶标有关。基于最佳的体重增加百分比（PWG），草鱼日粮中最佳的CIN补充剂估计为76.40 mg kg-1。通常，CIN增加草鱼的消化吸收能力，并提高AAT的mRNA丰度，这可能部分与TOR信号通路的激活有关。基于最佳体重增加百分比（PWG）的40 mg kg-1饮食。通常，CIN增加草鱼的消化吸收能力，并提高AAT的mRNA丰度，这可能部分与TOR信号通路的激活有关。基于最佳体重增加百分比（PWG）的40 mg kg-1饮食。通常，CIN增加草鱼的消化吸收能力，并提高AAT的mRNA丰度，这可能部分与TOR信号通路的激活有关。