Lv Weiwei, Li Muyan, Mao Yifan, Huang Weiwei, Yuan Quan, Li Mingyou, Zhou Qiubai, Yang Hang, Zhou Wenzong
Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Key Laboratory of Integrated Rice-Fish Farming, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China.
Comp Biochem Physiol Part D Genomics Proteomics. 2024 Dec;52:101273. doi: 10.1016/j.cbd.2024.101273. Epub 2024 Jun 10.
The objective was to assess the impact of melatonin supplementation on the growth performance and intestinal health of rice field eel, Monopterus albus. Three hundred and sixty fish (28.46 ± 0.24 g) were fed five diets supplemented with melatonin of 0, 30, 60, 120, and 240 mg/kg for 70 days. The study found that the variables FBW, WGR, SGR, and FCR exhibited a statistically significant quadratic relationship (P < 0.05) with the dietary melatonin concentrations, and the highest FBW, WGR and SGR as well as lowest FCR were observed in the 120 mg/kg melatonin group, digestive enzymes activities (such as amylase, trypsin, and lipase) also had significant quadratic relationship (P < 0.05), and the highest intestinal villus height and goblet cells were found in the 120 mg/kg diet (P < 0.01), melatonin in diets significantly increased SOD and CAT activities in serum, up-regulated the expression of anti-inflammatory factors (IL-10) and tight junction protein (ZO-1), and down-regulated the expression of pro-inflammatory factors (IL-1β, IL-8, IL-15, and TNF-α) in the gut, dietary melatonin improved the intestinal microflora compositions, in the group that supplementation a dosage of 120 mg/kg, there was a noticeable rise in the abundance of Firmicutes and the ratio of Firmicutes/Bacteroidota, compared with control group (P < 0.1). Conclusively, dietary supplementation of melatonin promoted growth performance, enhanced intestinal immune capacity and serum antioxidant level, and improved intestinal morphology properties and intestinal flora composition in M. albus. In conclusion, based on quadratic broken-line regression analysis of WGR and FCR, the optimal concentration of melatonin to be supplied is predicted to be 146-148 mg/kg.
目的是评估补充褪黑素对黄鳝生长性能和肠道健康的影响。将360尾黄鳝（体重28.46±0.24克）投喂添加了0、30、60、120和240毫克/千克褪黑素的五种饲料，为期70天。研究发现，终末体重（FBW）、增重率（WGR）、特定生长率（SGR）和饲料系数（FCR）与饲料中褪黑素浓度呈显著的二次关系（P<0.05），在120毫克/千克褪黑素组中观察到最高的FBW、WGR和SGR以及最低的FCR；消化酶活性（如淀粉酶、胰蛋白酶和脂肪酶）也呈显著的二次关系（P<0.05），在120毫克/千克饲料组中发现最高的肠绒毛高度和杯状细胞（P<0.01）；饲料中的褪黑素显著提高了血清中超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性，上调了抗炎因子（IL-10）和紧密连接蛋白（ZO-1）的表达，并下调了肠道中促炎因子（IL-1β、IL-8、IL-15和肿瘤坏死因子-α）的表达；饲料中的褪黑素改善了肠道微生物群落组成，在添加剂量为120毫克/千克的组中，厚壁菌门的丰度和厚壁菌门/拟杆菌门的比例与对照组相比有显著增加（P<0.1）。总之，饲料中添加褪黑素可促进黄鳝的生长性能，增强肠道免疫能力和血清抗氧化水平，并改善肠道形态特征和肠道菌群组成。基于WGR和FCR的二次折线回归分析，预测补充褪黑素的最佳浓度为146-148毫克/千克。
