饲料中茶多酚的添加量对团头鲂幼鱼生长、饲料利用和抗氧化能力的影响

为研究饲料中添加茶多酚对团头鲂幼鱼生长性能、饲料利用和抗氧化能力的影响，选取240尾初始体重为(3.5±1.0) g的团头鲂幼鱼，随机分为4组，每组3个重复，每个重复20尾。实验配制了茶多酚添加量分别为0 (对照组)、100、300和500 mg/kg的等氮等能饲料，饲喂团头鲂幼鱼8周后测定鱼体生长性能、肌肉组成、血液生化指标和肝肠抗氧化指标。结果显示，摄食300 mg/kg茶多酚组的增重率(WGR)相较于对照组显著提高，蛋白质效率(PER)显著高于低添加量组，饲料系数(FCR)显著降低。500 mg/kg茶多酚显著降低了鱼体肌肉粗脂肪含量。茶多酚的添加显著降低了血浆葡萄糖(GLU)含量，且300和500 mg/kg茶多酚添加组团头鲂肝肠丙二醛(MDA)含量均显著低于无添加组。100和300mg/kg茶多酚添加组鱼体肝肠组织中还原性谷胱甘肽(GSH)含量显著高于对照组。此外，300 mg/kg茶多酚添加组鱼体肝脏的总抗氧化能力(T-AOC)及谷胱甘肽过氧化物酶(GSHPx)活性也显著高于对照组。养殖实验结束后，通过腹腔注射浓度为50%的四氯化碳(CCl₄)溶液诱导...

Effects of different supplementation of dietary tea polyphenols on growth performance, feed utilization and antioxidant capacity of Megalobrama amblycephala

Research background] In recent years, with the rapid development of intensive aquaculture mode, aquatic diseases and environmental pollution has become an important factor limiting the healthy and sustainable development of aquaculture. The green and healthy development of "No antibiotics or alternative antibiotics" is the current demand and development trend of aquaculture industry, improve the anti-stress immunity of aquaculture animals, the development of antibiotic alternatives with immune promotion and nutritional growth function, is the urgent need to solve the problem of aquaculture industry development. Purpose] In order to study the effect of dietary tea polyphenols (TP) on the growth performance, feed utilization and antioxidant ability of Megalobrama amblycephala. Method] In the experiment, 240 Megalobrama amblycephala with an initial weight of (3.5±1) g were selected and randomly divided into 4 groups of 3 replicates each with 20 fish in each replicate. Four isonitrogen isoenergetic formulation diets supplemented with 0 mg/kg (control group), 100 mg/kg, 300 mg/kg and 500 mg/kg tea polyphenols were prepared. After the 8 weeks feeding trial, the growth performance, muscle composition, blood biochemical indicators , liver antioxidant indicators and intestinal antioxidant indicators were measured. Results] The results showed that the weight gain rate (WGR) of the fish fed 300 mg/kg TP were significantly higher than those of the control group (P<0.05), the protein efficiency (PER) was significantly higher than those with lower supplementary TP (P<0.05), and the feed coefficient (FCR) decreased significantly (P<0.05). 500 mg/kg TP supplementation significantly reduced the crude fat content of fish muscle (P<0.05). The TP supplementation significantly reduced plasma glucose (GLU) content (P<0.05). The content of malondialdehyde (MDA) in the liver and intestines of fish fed 300 mg/kg and 500 mg/kg TP supplementary diets were significantly lower than those in the control group . The content of reduced glutathione (GSH) in the liver and intestine tissues of fish fed 100 mg/kg and 300 mg/kg dietary TP were significantly higher than that in the control group (P<0.05). In addition, the hepatic total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) activity of the 300 mg/kg TP supplementary group were also significantly higher than those in the control group (P<0.05). After the feeding trial, acute liver injury was induced by intraperitoneal injection of 50% concentration of CCl4 solution. It was found that at 24 hours post-injection, the fish survival rates of the 300 mg/kg and 500 mg/kg TP supplementary groups were significantly higher than those of the 100 mg/kg TP supplementary group (P<0.05), and the survival rates in 100 mg/kg TP supplementary group was further significantly higher than the control group (P<0.05). Further analysis on the hepatic antioxidant indexes of fish at 24 hours post-injection, we found that the hepatic MDA content was significantly reduced in the TP supplementary groups (P<0.05). The activity of oxide dismutase (SOD) of the 500 mg/kg TP supplementary group were significantly higher than those in the control group (P<0.05), the content of educed glutathione (GSH) of the 300 mg/kg TP supplementary group were significantly higher than those in the control group (P<0.05). Conclusion] Considering the physiological effects and practical applications, the dietary supplementation of 300 mg/kg tea polyphenols effectively promoted the growth and feed utilization of Megalobrama amblycephala juveniles, and further improve the antioxidant and anti-injury capacities. Meaning] The results of this study provide a basis for the study of tea polyphenols in the feeds of pomfrets and provide a reliable reference for their better application in breeding production.