A 30‐day feeding trial was conducted to investigate the effects of dietary silymarin (SM) on growth performance, digestive enzyme activities, antioxidant capacity and lipid metabolism in large yellow croaker larvae (initial weight: 4.71 ± 0.21 mg). Four iso‐nitrogenous and iso‐lipidic diets were formulated with 0, 50, 150 and 450 mg/kg of SM, respectively. Results showed that larvae‐fed diets with 50 and 150 mg/kg SM had higher specific growth rate and weight gain rate than the control group (p < .05). Activities of trypsin in larval intestinal segments and lipase in larval pancreatic segments were significantly increased in larvae‐fed diet with 50 mg/kg SM compared to the control group (p < .05). Total antioxidant capacity in larvae‐fed diet with 50 mg/kg SM was higher than the control group (p < .05). Meanwhile, malondialdehyde contents were lower in larvae‐fed diets with 50 and 150 mg/kg SM than the control group (p < .05). The triglyceride content in visceral mass was lower in larvae‐fed diets with 50 and 150 mg/kg than the control group (p < .05). Results of gene expression revealed that dietary SM reduced visceral mass lipid accumulation probably through inhibiting lipid synthesis‐related genes (srebp‐1 and fas) and promoting lipid oxidation‐related genes (pparα and cpt‐1) at the transcriptional level. In summary, results of the present study indicated that the supplementation of 50 mg/kg SM could improve growth performance, digestive enzyme activities and antioxidant capacity, and reduce visceral mass lipid accumulation in large yellow croaker larvae.

中文翻译：

---

日粮水飞蓟素（SM）对大黄鱼（Larimichthys crocea）幼虫生长性能，消化酶活性，抗氧化能力和脂质代谢基因表达的影响

进行了为期30天的喂养试验，研究了水飞蓟素（SM）对大黄鱼幼鱼（初始体重：4.71±0.21 mg）的生长性能，消化酶活性，抗氧化能力和脂质代谢的影响。分别以0、50、150和450 mg / kg的SM配制四种等氮和等脂饮食。结果表明，幼虫喂养的日粮SM分别为50和150 mg / kg，比对照组的比生长率和体重增加率更高（p  <.05）。与对照组相比，以50 mg / kg SM喂养的幼虫喂养日粮中，幼虫肠段中胰蛋白酶的活性和幼虫胰腺段中的脂肪酶的活性显着增加（p <.05）。以50 mg / kg SM喂养的幼虫饲料中的总抗氧化能力高于对照组（p  <.05）。同时，以50和150 mg / kg SM喂养的幼虫饲粮中的丙二醛含量低于对照组（p  <.05）。幼虫喂养的日粮分别为50和150 mg / kg时，内脏质量中的甘油三酯含量比对照组低（p  <.05）。基因表达结果表明，饮食SM可能通过抑制脂质合成相关基因（srebp-1和fas）和促进脂质氧化相关基因（pparα和cpt-1）来减少内脏脂肪堆积。在转录水平上。综上所述，本研究结果表明，添加50 mg / kg SM可以改善大黄鱼幼虫的生长性能，消化酶活性和抗氧化能力，并减少内脏质量脂质的积累。