Wang Shixin

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.

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。