The efficacy of p‐coumaric acid (CA) on growth performance, digestive enzyme activity, humoral immunity and immune gene expressions of common carp (Cyprinus carpio) was tested in the present study. Fish were fed diets supplemented with 0, 0.5, 1 and 1.5 g/kg CA for 56 days. According to regression analysis, specific growth rate (SGR), feed conversion ratio (FCR) and weight gain (WG%) were polynomially related to dietary CA levels. The optimum p‐coumaric acid supplementation level, based upon these parameters, was 1.35%–1.44%. Furthermore, dietary CA supplementation at levels of 1.0 and 1.5 g/kg significantly improved the serum immune parameters (total Ig, lysozyme and ACH50). Dietary CA especially at 1.0 and 1.5 g/kg increased the intestinal IL‐8 and TNF‐α, while not affecting the expression of IL‐1β and lysozyme gene. The highest and lowest mortality rates 14 days postchallenge with A. hydrophila were recorded in fish fed control and 1.5 g/kg CA, respectively. In conclusion, the oral administration of CA especially at 1 and 1.5 g/kg inclusion levels has the potential to improve growth performance, digestive enzyme activity and immune responses of common carp.

中文翻译：

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日粮对香豆酸对鲤鱼生长性能，消化酶活性，体液免疫和免疫相关基因表达的影响

的功效p生长性能，消化酶活性，体液免疫和鲤鱼（免疫基因表达香豆酸（CA）鲤）在本研究中进行了测试。鱼补充了0、0.5、1和1.5 g / kg CA的饲料，饲喂了56天。根据回归分析，比生长速率（SGR），饲料转化率（FCR）和增重（WG％）与膳食CA水平呈多项式关系。根据这些参数，对-香豆酸的最佳添加量为1.35％–1.44％。此外，饮食中添加1.0和1.5 g / kg的CA可以显着改善血清免疫参数（总Ig，溶菌酶和ACH50）。饮食中的CA尤其是1.0和1.5 g / kg的肠内IL-8含量增加和TNF-α，但不影响IL-1β和溶菌酶基因的表达。最高和最低的死亡率14天攻击后嗜水被记录在鱼供给的控制和1.5g / kg的CA，分别。总之，口服CA，尤其是以1和1.5 g / kg的夹杂水平口服，有可能改善鲤鱼的生长性能，消化酶活性和免疫反应。