植物油部分替代饲料中鱼油对大黄鱼脂肪及脂肪酸的影响

Effect of partial replacement of fish oil with vegetable oil on muscle and liver total lipid and fatty acid of larvae Larmichthys crocea

摘要:

为了研究植物油部分替代饲料中鱼油对大黄鱼(Larmichthys crocea)幼鱼生长、肌肉和肝脏总脂肪及脂肪酸的影响,以鱼油含量6%组(A组)为对照组,菜籽油替代16.67%(B组)、33.33%(C组)、50.00%(D组)、66.67%(E组)及混合植物油(棕榈油:紫苏油:菜籽油=3.6:2.5:1)替代66.67%(F组)鱼油为实验组,共6种等氮等能饲料饲养大黄鱼幼鱼[初重(0.65±0.11)g]50 d。结果表明,植物油处理组(B、C、D、E和F组)的终末体重、相对增重率、特定生长率与A组无显著性差异;C组,D组和E组的存活率显著低于A组;各处理组间饲料系数无显著性差异。植物油替代鱼油显著影响肌肉粗蛋白含量,A组的粗蛋白含量最低(58.9%±0.41%);各组粗灰分无显著性差异;植物油替代鱼油不影响肌肉与肝脏的总脂肪含量,但显著影响肌肉与肝脏的脂肪酸组成。随着菜籽油替代水平的提高,肌肉中18:3n3以及肝脏中18:1,18:2n6,18:3n3的绝对含量显著提高,而EPA和DHA绝对含量均显著下降。与相同水平的菜籽油替代组相比,混合植物油替代组肌肉中EPA、DHA以及肝脏中18:3n3的绝对含量显著升高,而肝脏中EPA和DHA的绝对含量显著降低。研究表明,66.67%的菜籽油或者植物混合油替代鱼油饲养大黄鱼幼鱼6周不影响其生长但降低鱼体的脂肪酸营养价值。

Abstract:

A 50-day feeding trial was conducted to investigate the effect of partial replacement of fish oil with vegetable oil on growth, muscle and liver total lipid and fatty acid of larvae Larmichthys crocea(initial weight 0.65g±0.11g).Six isonitrogenous and isoenergetic experimental diets were formulated.The control feed(Group A) was formulated with 6% fish oil, whereas the other 5 experimental diets were formulated by replacing the fish oil with 16.67% rapeseed oil(Group B),33.33% rapeseed oil(Group C),50% rapeseed oil(Group D),66.67% rapeseed oil(Group E), and 66.67% blended vegetable oil(Group F,palm oil:perillaoil:rapeseed oil=3.6:2.5:1),respectively. Results showed that these replacements(Group B,C,D,E and F) did not significantly influence the final weight, weight gain, specific growth rate compared with Group A; the survival rate of Group C, D and E was lower than Group A;the feed coefficient had no significant difference among the six experimental groups.Partial replacement of fish oil with vegetable oil significantly influenced the content of muscle protein, and Group A had the lowest content of muscle protein(58.9%±0.41%); ash had no significant difference among the six experimental groups. Though there was no significantly influence on the content of total lipid on muscle and liver among six experiment groups, the composition fatty acids was significant influenced. With the increasing replacment by rapeseed oil, the contents of 18:3n3 in muscle and the contents of 18:1,18:2n6,18:3n3 in liver were significantly increased, whereas the contents of EPA and DHA were significantly decreased. Compared with the same level of rapeseed replaced group, the contents of EPA,DHA in muscle and the contents of 18:3n3 in liver in blended vegetable oil group were significantly increased, whereas the contents of EPA and DHA in liver were significantly decreased. This study suggested that replacing 66.67% fish oil with rapeseed oil or with blended vegetable oil fed larvae Larmichthys crocea for 6weeks did not influence its growth, but reduced its nutritional value of fatty acid.