植物甾醇对黄颡鱼幼鱼生长性能、肝胰脏抗氧化功能和攻毒试验的影响

Effects of phytosterol on growth performance,antioxidant function in hepatopancreas and reaction after injecting Aeromonas hydrophylia of juvenile Yellow catfish(Pelteobagrus fulvidraco)

本试验旨在研究饲料中添加植物甾醇对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长性能、体成分、肝胰脏抗氧化功能及攻毒试验的影响。把600尾初重约为(1.64+0.01)g的黄颡鱼随机分到15个养殖桶中,每个桶放养40尾鱼。试验设计五个植物甾醇浓度梯度,添加量依次为0、20、40、60、80 mg/kg,每个梯度有3个重复,分别对应15个养殖桶。每个试验组投喂对应组饲料,组别按浓度依次记为PS0、PS20、PS40、PS60和PS80,其中PS0为对照组。结果表明:(1)与PS0组对比,其余四组黄颡鱼幼鱼的终末体重、增重率、特定生长率和蛋白质效率均得到提升,PS40组达到最大值,分别比PS0组提高6.3%、5.9%、2.0%、10.3%,随后下降,且PS40组终末体重与增重率,PS20和PS40组特定生长率,PS20~PS60组蛋白质效率显著高于PS0组(P<0.05);PS20~PS80组饲料系数均低于PS0组,且PS40组显著下降(P<0.05)。(2)与PS0组对比,其余四组黄颡鱼幼鱼的形体指标没有显著变化(P>0.05);植物甾醇有提高黄颡鱼幼鱼体成分中粗蛋白质含量和降低体成分中粗脂肪含量的趋势,其中PS40、PS60和PS80组粗蛋白质含量显著提高5.9%、5.3%、4.6%(P<0.05),PS40和PS60粗脂肪含量降低10.7%、11.8%(P<0.05)。(3)饲料中添加植物甾醇能够提升黄颡鱼幼鱼肝胰脏的抗氧化能力。PS40、PS60和PS80组超氧化物歧化酶活力显著提高40.2%、21.1%、16.1%(P<0.05),总抗氧化能力显著提高17.6%、10.3%、14.7%(P<0.05),PS40和PS60组过氧化氢酶活力较PS0组显著提高9.3%、38.3%(P<0.05);与PS0组对比,其余四组丙二醛含量显著降低9.3%、14.3%、14.8%、11.5%(P<0.05)。(4)与PS0组相比,PS40、PS60和PS80组的24 h死亡率显著下降22.7%、18.2%、18.2%(P<0.05),PS20~PS80组的48 h死亡率显著下降11.11%、22.2%、22.2%、18.5%(P<0.05)。综上所述,饲料中添加一定量的植物甾醇可以明显提高黄颡鱼幼鱼的生长性能和饲料利用,提升肝胰脏的抗氧化能力和降低感染嗜水气单胞菌后的死亡率。

This experiment was conducted to study effects of phytosterol on growth performance,body composition,antioxidant function in hepatopancreas and reaction after injecting Aeromonas hydrophylia of juvenile Yellow catfish(Pelteobagrus fulvidraco).Six hundred individuals of Yellow catfish with an average body weight of(1.64±0.01)g were randomly allotted to five dietary treatments with three replicates of each 40individuals and fed basal diet supplemented with 0(PS0),20(PS20),40(PS40),60(PS60),80(PS80)mg/kg phytosterol for sixty days.The results showed as follows:(1)With the dietary phytosterol additive amount increased,the final body weigh,weight gain rate,specific growth rate and protein efficiency rate increased at first but then decreased,achieving the maximum value at PS40,respectively up to 6.3%,5.9%,2.0%,10.3%.Compared with PS0,final body weigh and weight gain rate of PS40,specific growth rate of PS20 and PS40,protein efficiency of PS20~PS60 increased significantly(P<0.05).Feed coefficient ratio of PS20~PS80decreased,PS40 decreased significantly(P<0.05).(2)Phytosterol had no significant effect on physique index of juvenile Yellow catfish(P>0.05).Yellow catfish crude protein of PS40,PS60 and PS80 was significantly higher than PS0,respectively up to 5.9%,5.3%,4.6%(P<0.05),however,crude lipid of PS40 and PS60 was significantly lower,respectively down to 10.7%,11.8%(P<0.05).(3)Phytosterol could enhanced liver antioxidant capacity of juvenile Yellow catfish.Compared with PS0,superoxide dismutase activity and total antioxidant of PS40~PS80 increased significantly,respectively up to 40.2%,21.1%,16.1%and 17.6%,10.3%,14.7%(P<0.05),catalase activity of PS40 and PS60 increased significantly,respectively up to 9.3%,38.3%(P<0.05),malondialdehyde of PS20~PS80 decreased significantly,respectively down to 9.3%,14.3%,14.8%,11.5%(P<0.05).(4)Phytosterol could reduced 24 h mortality rate and 48 h mortality rate of juvenile Yellow catfish infected with Aeromonas hydrophylia.24 h mortality rate of PS40~PS80 was significantly lower than PS0,respectively up to 22.7%,18.2%,18.2%(P<0.05),48 h mortality rate of PS20~PS80 was significantly lower than PS0,respectively down to 11.11%,22.2%,22.2%,18.5%(P<0.05).As a conclusion,the proper amount of diet phytosterol could improve growth performance of juvenile Yellow catfish,strengthen its liver antioxidant function,lower its mortality rate after infecting with Aeromonas hydrophylia.