富硒壶瓶碎米荠对青鱼幼鱼生长、生理生化、硒代谢、抗氧化及先天免疫的影响

为探究富硒壶瓶碎米荠(Cardamine hupingshanensis)对青鱼(Mylopharyngodon piceus)幼鱼生长、血清生理生化、肝脏硒代谢、抗氧化能力和先天免疫指标的影响,选取360尾初始体重为(5.51±0.02) g的青鱼幼鱼随机分配至4个实验组中,每组3个重复。在基础饲料中添加富硒壶瓶碎米荠的量为0、0.5、1.0和2.0 g/kg(硒的实际含量分别为0.04、0.43、0.75和1.57 mg/kg),同时添加矿物质混合物(无硒添加)和维生素混合物,配置成4种等氮等能的青鱼幼鱼试验饲料,养殖周期为60d。结果显示:饲料中添加0.5和1.0 g/kg富硒壶瓶碎米荠时,鱼体增重率(WG),特定生长率(SGR)较对照组和过量组(2.0 g/kg)显著升高,饲料系数(FCR)显著降低(P<0.05)。当饲料中富硒壶瓶碎米荠添加量为0.5—1.0 g/kg时,血清中的甘油三酯(TG)、总胆固醇(TCH)和白蛋白(ALB)含量呈上升趋势,而葡萄糖(GLU)含量显著下降(P<0.05)。饲料中添加0.5—1.0 g/kg富硒壶瓶碎米荠时可显著提高肝脏核因子...

SELENIUM-RICH CARDAMINE HUPINGSHANENSIS ON GROWTH,BIOCHEMICAL INDICES,SELENIUM METABOLISM,ANTIOXIDANT CAPACITIES AND INNATE IMMUNITIES IN JUVENILE BLACK CARP (MYLOPHARYNGODON PICEUS)

In order to investigate the effects of different levels of dietary selenium-rich Cardamine hupingshanensis on the growth performance, physiological and biochemical parameters, selenium metabolism, antioxidant capacities and innate immunities in black carp (Mylopharyngodon piceus), 360 juvenile black carps with initial body weight of (5.51±0.02) g were randomly divided into four groups, and each group had 3 replicates. Four levels of selenium-rich C. hupingshanensis (0, 0.5, 1.0 and 2.0 g/kg) (selenium levels 0.04, 0.43, 0.75 and 1.57 mg/kg) were added and made four isonitrogenous and isoenergetic diets. The culture period was conducted for 60 days. The results showed that adequate selenium-rich C. hupingshanensis (0.5 and 1.0 g/kg) could significantly increase the weight gain rate (WGR) and specific growth rate (SGR), while significantly decrease the feed conversion ratio (FCR), comparing with the control group and the excessive group (2.0 g/kg) (P<0.05). In the fish body composition, the crude protein levels were significantly increased in fish fed with 1.0 g/kg selenium-rich C. hupingshanensis, and then decreased at 2.0 g/kg selenium-rich C. hupingshanensis. Adequate supplemental level of selenium-rich C. hupingshanensis (0.5 and 1.0 g/kg) could significantly increase the serum albumin (ALB), triglycerides (TG) and total cholesterol (TCH), while decrease serum glucose (GLU) levels. Higher activities of superoxide dismutase (SOD), the catalase (CAT) and glutathione peroxidase (GSH-PX), levels of total antioxidant capacities (T-AOC), and the glutathione (GSH) (P<0.05) were shown in the liver of fish fed adequate supplemental level of selenium-rich C. hupingshanensis. Meanwhile, adequate supplemental level of selenium-rich C. hupingshanensis could significantly increase expression level of nuclear factor-erythroid-2-related factor 2 (Nrf2), Mn-superoxide dismutase (Mn-SOD), catalase (CAT), glutathione peroxidase 1 (GPX1) and glutathione peroxidase 4 (GPX4), while decrease the expression level of Kelch-like-ECH-associated protein 1 (Keap1) in the fish liver (P<0.05). In addition, adequate supplemental level of selenium-rich C. hupingshanensis significantly increase expression level of selenium-metabolic proteins, including selenocysteine lyase (SCLY), selenide, water dikinase 1 (SPS1), 15kDa selenoprotein (SEP15), selenoprotein T2 (SEPT2), selenoprotein H (SEPH), selenoprotein P (SEPP) in the liver of juvenile black carp compared with the control group (P<0.05). Furthermore, the expression level of innate immune defense molecules, including liver-expressed antimicrobial peptide 2 (Leap2), hepcidin (HEPC), lysozyme (LYS) and complement 3 (C3) were significantly up-regulated by adequate supplemental level of selenium-rich C. hupingshanensis (P<0.05). In conclusion, these results suggest that the adequate dietary supplemental level of selenium-rich C. hupingshanensis could significantly increase growth performances, promote the selenium metabolism, improve antioxidant capacities and enhance innate immunities in black carp.