Wang Jiying

A comparative study on fatty acid composition in different tissues of the wild and cultured Paralichthys olivaceus broodstocks

Lipid contents and fatty acid composition in muscle,liver and egg of the wild and cultured Paralichthys olivaceus broodstocks were determined by biochemical methods,to ascertain their effects on the reproductive performance.The results indicated that lipid contents in muscle,liver and egg of both wild and cultured broodstocks were as follows: liver egg muscle.The lipid contents in muscle and egg of wild broodstocks were significantly lower than those of cultured(P0.05),while there were no differences of lipid content in liver between the wild and cultured;21 fatty acids were detected in muscle,liver and egg.There were no differences of SFA in muscle between the wild and cultured(P0.05),but MUFA was sig-nificantly lower than that of cultured(P0.05).SFA in liver and egg of wild broodstocks was significantly higher than that of cultured(P0.05),but there were no differences of MUFA in liver and egg between wild and cultured(P0.05);The PUFA,especially EPA and DHA in muscle,liver and egg of wild were signifi-cantly lower than those of cultured(P0.05),but ARA of wild was significantly higher(P0.05);The ratio of n-3/n-6 PUFA and EPA/ARA in muscle,liver and egg of wild were significantly lower than those of cultured(P0.05),the ratio of DHA/EPA in liver of wild was significantly higher(P0.05),while there were no differences of the ratio of DHA/EPA in muscle between wild and cultured(P0.05).Results of this study indicated that,PUFA,especially DHA,EPA and ARA,could be conjectured to be essential to P.olivaceus during sexual maturation.Thus,in order to ensure the reproductive performance and quality of egg and fry,an adequate supply of fatty acids was needed,meanwhile,the proportion of several fatty acids,especially PUFA,also needed to be considered.

饲料花生四烯酸水平对珍珠龙胆石斑鱼幼鱼生长性能、抗氧化能力、血清生化指标以及肝脏和肌肉脂肪酸组成的影响

本试验旨在研究饲料花生四烯酸（ARA）水平对珍珠龙胆石斑鱼幼鱼生长性能、抗氧化能力、血清生化指标以及肝脏和肌肉脂肪酸组成的影响。通过在基础饲料中添加ARA纯化油，制成ARA水平分别为0.04%、0.17%、0.35%、0.66%、1.29%和2.16%（干物质基础）的等氮等脂的试验饲料（分别命名为S1、S2、S3、S4、S5和S6）。将上述饲料投喂初始体重为（23.77±0.98）g的珍珠龙胆石斑鱼幼鱼，每种饲料设3个重复，每个重复投喂30尾鱼，试验期为8周。结果表明：1）特定生长率（SGR）和饲料效率（FE）随饲料ARA水平的升高均呈先升高后降低的趋势，且SGR和FE均在S4组有最大值，均显著高于S1组（P 0.05），但显著高于S1与S6组（P < 0.05）。S3与S4组肝脏丙二醛（MDA）含量显著低于S1和S6组（P < 0.05）。3）血清中谷草转氨酶（AST）、谷丙转氨酶（ALT）和碱性磷酸酶（AKP）活性均在S4组最低，且显著低于S1与S6组（P < 0.05）。4）肝脏和肌肉中C20：3n-6和C20：4n-6含量随饲料ARA水平的提高而显著升高（P < 0.05），而C18：3n-6、C20：5n-3和C22：6n-3含量则随之有不同程度的下降。由此得出，饲料中适宜水平（0.35%~0.66%）的ARA能够促进珍珠龙胆石斑鱼幼鱼的生长，提高抗氧化能力与肝脏健康水平，以SGR与FE作为评价指标，经折线模型回归分析得出珍珠龙胆石斑鱼幼鱼饲料中ARA的适宜水平分别为饲料干重的0.45%和0.56%。

VE和L-肌肽对大菱鲆幼鱼生长、抗氧化、非特异性免疫及血清生化指标的影响

实验以大菱鲆（ Scophthalmus maximus ）幼鱼[（14.00±0.02）g]为研究对象，采用2×4双因素设计，设2个VE水平（0和75 mg/kg）和4个L-肌肽水平（0、50、100和200 mg/kg），研究VE和L-肌肽对其生长、抗氧化、非特异性免疫及血清生化指标的影响。实验共分8组，每组3个重复，每个重复46尾鱼，实验周期为8周。结果显示：（1）在饲料中添加75 mg/kg VE显著提高了大菱鲆幼鱼增重率（ WGR ）和特定生长率（ SGR ）（ P P >0.05），添加量为200 mg/kg时鱼体 WGR 、 SGR 和蛋白质效率（ PER ）显著降低，饲料系数（ FCR ）显著升高（ P P P >0.05），添加100 mg/kg肝脏T-AOC和SOD活性达到最高且50 mg/kg组的SOD与100 mg/kg组差异不显著（ P >0.05），主效应结果显示，VE显著提高了血清T-AOC、SOD及肝脏CAT活性（ P P C 3和LZM活性交互作用显著，在75 mg/kg VE水平下，L-肌肽添加量为50 mg/kg时，补体 C 3水平最高（ P P >0.05）；（4）添加VE显著降低了血清总胆固醇（TCHO）和甘油三酯（TG）含量（ P < 0.05），添加L-肌肽显著降低了血清TG含量，且在L-肌肽50 mg/kg时达到最低。综合考虑大菱鲆幼鱼[（14.00-39.43）g]的生长性能、抗氧化性能、非特异性免疫及血清生化指标得出，在实验配方条件下（鱼油70 g/kg，大豆卵磷脂10 g/kg），添加VE 75 mg/kg时，L-肌肽的适宜添加量为50 mg/kg。

微粒饲料中以微藻粉替代鱼油对牙鲆( Paralichthys olivaceus )稚鱼生长存活和脂肪酸组成的影响

以18日龄的牙鲆(Paralichthys olivaceus)稚鱼为研究对象，通过11 d的生长实验，研究了添加不同比例的微藻粉替代鱼油对牙鲆稚鱼生长、存活率和脂肪酸组成的影响。以鱼油组(FO)为对照组，以裂壶藻粉(Schizochytrium sp.)、微绿球藻粉(Nannochloropsis sp.)和橄榄油替代不同比例的鱼油，配制成5组等氮等能的实验饲料，分别命名为鱼油组(FO)，50%混合替代组(M50)、100%混合替代组(M100)、100%裂壶藻橄榄油替代组(S100)、100%微绿球藻橄榄油替代组(N100)。结果显示, 微藻粉替代鱼油对牙鲆稚鱼的生长无显著影响；含有裂壶藻的各饲料组(M50、M100、S100)成活率显著高于FO组和N100组(P˂0.05)；微藻粉替代鱼油不影响牙鲆稚鱼主要脂肪酸的组成；Person相关性分析发现，C14:0、C16:1n-7、C18:2n-6、C20:0、C18:3n-3、C22:0、C20:4n-3、EPA、C22:5n-6和DHA的百分含量均与其饲料中的百分含量呈显著正相关(P < 0.05)；总饱和脂肪酸、总单不饱和脂肪酸、n-3多不饱和脂肪酸的百分含量以及DHA/EPA比率均与其饲料组成表现出显著正相关(P < 0.05)。综上所述，微藻作为脂肪源替代鱼油完全可以满足牙鲆稚鱼的生长和发育，各种脂肪酸均可以被牙鲆稚鱼充分消化和吸收，并且添加两种微藻后提高了稚鱼的DHA含量和DHA/EPA比率，与鱼油对照组相比显著提高了牙鲆稚鱼的成活率。因此，以微藻替代鱼油在牙鲆稚鱼的培育中是可行的。