饲料中植物油替代鱼油对中华绒螯蟹脂肪酸组成的影响

为研究饲料中植物油替代鱼油对中华绒螯蟹脂含量及脂肪酸组成的影响,采用植物油m(豆油)∶m(菜籽油)=3∶1]替代不同水平(0%、50%和100%)的鱼油,制成3种等氮等脂饲料(F1、F2和F3)喂养3组成体雌蟹70 d。结果显示,3组蟹的体肉、性腺和肝胰腺的粗脂肪含量无显著性差异(P0.05)。各组饲料的脂肪酸组成有所不同,体肉中多不饱和脂肪酸(polyunsaturated fatty acid, PUFA)占比约50%,其含量无显著性差异(P0.05);性腺中n-6 PUFA含量随着替代水平的升高而升高;肝胰腺受饲料中植物油替代鱼油的影响最大,单不饱和脂肪酸(monounsaturated fatty acid, MUFA)及PUFA总含量都随着替代水平的升高而升高;与F1、F3组相比,F2组3个可食部位的EPA+DHA含量均较高。综上所述,使用50%植物油替代鱼油饲料喂养雌性中华绒螯蟹对其可食部位的脂肪酸组成有正面作用。本研究为优化育肥饲料中鱼油替代源配比以及进一步改善中华绒螯蟹品质等提供了一定的依据。

Effects of dietary replacement of fish oil by vegetable oil on fatty acid composition of Chinese mitten crab (Eriocheir sinensis)

In order to study the effect of dietary replacement of fish oil by vegetable oil on the crude lipid content and fatty acid composition of Chinese mitten crab, vegetable oil (W (soybean oil): W (rapeseed oil) =3:1) was used to replace different levels (0%, 50% and 100%) of fish oil to make three kinds of feeds with equal nitrogen and fat (F1, F2 and F3). The results showed that there was no significant difference (P > 0.05) in the crude fat content between the meat, gonads and hepatopancreas of three groups of crabs. The fatty acid composition of each feed was different. The content of polyunsaturated fatty acid (PUFA) in meat was about 50%, and there was no significant difference (P > 0.05) among dietary groups. The gonad fatty acid composition was affected by the fatty acid composition of feed. The content of n-6 PUFA increased with the increase of the replacement level. The hepatopancreas fatty acid composition was the most affected by the substitution of vegetable oil in the feed for fish oil, and the total content of monounsaturated fatty acid (MUFA) and PUFA increased with the replacement level. The content of n-3 PUFA in hepatopancreas of F2 was significantly (P < 0.05) higher than that of the other two groups, and the content of EPA+DHA in the three edible parts was higher. Therefore, it could be seen that 50% vegetable oil replacing fish oil was beneficial to the fatty acid composition of edible parts of female Chinese mitten crab, which provided a reference for the substitution ratio of fish oil in the fattening feed and further influence on the quality.