为了探究牛磺酸对脂质氧化饲料饲喂下黄河鲤生长性能和肠道健康的影响，实验先用等量的氧化鱼油 (记为OFO)替换基础日粮 (记为FO)中的新鲜鱼油，接着将不同含量 (0.4%、0.8% 和1.2%，质量分数)的牛磺酸分别加入OFO组饲料中 (分别记为T0.4、T0.8和T1.2)，对初始体重为 (8.74±0.01) g的黄河鲤进行为期10周的养殖实验。结果显示，与FO组相比，OFO组的终末体重、增重率、特定增长率和饲料效率均显著降低。上述所有指标在T0.4、T0.8和T1.2组中均显著高于OFO组。适量牛磺酸可抑制氧化脂质饮食引起的nrf2 mRNA表达水平的降低和keap1 mRNA表达水平的升高，并且显著提高受Nrf2调控的下游转录因子 (gr、gpx和sod)的mRNA表达水平。牛磺酸还能缓解氧化脂质饲料引起的肠道消化酶活性、绒毛高度、绒毛宽度和肌层厚度的降低。另外，OFO组中肠道微生物组成的丰度和多样性显著降低，条件致病菌丰度明显升高，而有益菌的丰度却有所下降，这些不良现象在牛磺酸组中均得到明显改善。研究表明，牛磺酸可缓解脂质氧化饲料对黄河鲤造成的生长性能抑制、肠道组织结构破坏、消化功能下降及肠道菌群紊乱等不良影响。结合本研究结果，在氧化脂质饲料中牛磺酸的建议添加剂量为0.4%~0.8%。本研究为进一步探索牛磺酸对鱼类肠道的生物学功能奠定理论基础。

Lipid oxidation is prevalent in fish feed, which reduces the nutritional value of fish feed and damages the health of aquatic animals. Taurine has been extensively studied as a feed additive to promote fish growth and antioxidant capacity, but its effects on intestinal health need further research. To investigate the effects of taurine on the growth performance and intestinal health of the Yellow River carp (Cyprinus carpio) fed with a lipid-oxidized diet, a total of 225 C. carpio with similar weight at about 8.74 g were randomly divided into five groups: FO, OFO, T0.4, T0.8, and T1.2, respectively. A 10-week feeding trial was performed. The results showed that taurine supplementation alleviated the growth inhibition caused by the OFO diet on C. carpio, mainly by improving final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), and feed efficiency (FE). The oxidized lipid diet inhibited nrf2 mRNA expression in the hepatopancreas and intestine and promoted the mRNA levels of keap1 in the intestine. Appropriate taurine addition can inhibit the decrease of nrf2 mRNA levels and increase of keap1 mRNA levels induced by the OFO diet. Taurine also increased mRNA levels of antioxidation-related genes (gr, gpx and sod). For example, supplementation of 0.8 g/kg taurine significantly increased intestinal gr, gpx, and sod expression levels. In addition, taurine mitigated the decreased intestinal digestive enzyme activity (lipase, amylase, and trypsin), villus height, villus width, and muscular thickness of the oxidized lipid diet. Moreover, taurine restored the decreased alpha-diversity index (Chao1, observed species, Shannon, and Simpson index) of intestinal flora induced by the oxidized lipid diet. Furthermore, supplementation of 0.8% taurine reversed intestinal flora disturbance caused by the oxidized lipid diet, mainly by reducing the abundance of pathogenic bacteria (Aeromonasd and Acinetobacter, etc.) and increasing the abundance of beneficial bacteria (Lactobacillus, Cetobacterium, and Prevotella, etc.). In conclusion, taurine mitigated the negative effects of lipid oxidized diet on the growth performance and intestinal health of C. carpio, and the recommended supplemental level of taurine in the oxidized lipid diet was 0.4%–0.8%. This study lays a theoretical foundation for further exploring the biological function of taurine in fish intestines.

S 963.73⁺1

国家自然科学基金 (32072991, U22A20532)；河南省现代农业产业技术体系建设专项 (HARS-22-16-G2)；河南师范大学创新科技队伍建设项目 (2020TD02)