【作者】 周继术；

【导师】 叶元土；

【作者基本信息】 西南农业大学 ， 生物化学与分子生物学， 2001， 硕士

【摘要】 脂肪是水生动物重要的营养物质，对水生动物的生长、发育和维持正常生理代谢等均具有非常重要的作用。水生动物的必需脂肪酸包括n-3系列、n-6系列的两大类脂肪酸。饲料必需脂肪酸对于水生动物的营养价值主要决定于水生动物所需的必需脂肪酸的需要量是否得到满足、必需脂肪酸的种类是否完全以及n-6系列与n-3系列脂肪酸的比例关系是否平衡。 不同种类的水生动物对必需脂肪酸的需要是有差异的，不同的油脂对同一种水生动物的营养价值也是不相同的。本项目主要是以雄性化的奥尼罗非鱼为试验材料，在使用6种单一油脂原料进行养殖试验的基础上，按照奥尼罗非鱼对必需脂肪酸的需要，通过油脂的组合比例来调整配合饲料中必需脂肪酸的种类、含量和n-3系列、n-6系列脂肪酸的比例关系，以生长速度、饲料效率、鱼体品质(形体指数和生化组成)、相关酶活力、脂肪代谢中间产物(酮体)等为检测指标，探讨必需脂肪酸对奥尼罗非鱼的生长效果和作用机理。 试验一：6种油脂对奥尼罗非鱼生长的影响 以尾均重65．5土4．0g奥尼罗非鱼鱼种为试验动物，随机分为6个组，每组约30尾。将棉籽油、大豆油、菜籽油、芝麻油、猪油、牛油按3％水平分别加入相同的基础饲料中，制得6种配合饲料并分别饲喂6组试验罗非鱼，经过35天的常规养殖试验得到如下结果： (1)生长速度：日增重率(％)以芝麻油组最高，为2．10；大豆油组次之为1．77；菜籽油组为1．51；以下为棉籽油组(1．44)、牛油组(1．40)和猪油组(1．34)。 (2)饲料效率(％)：以芝麻油组最高为55．17；菜籽油组次之，为53．7；以下为大豆油组(53．14)、棉籽油组(48．60)、牛油组(42．36)和猪油组(42．35)。 (3)对鱼体品质的影响：①鱼体生化组成：各试验组鱼体水分、灰分、钙、磷含量(％)差异不显著(P〉0．05)，但在粗蛋白质与粗脂肪含量上有显著差异(P<0．05):粗蛋白质含量（%）以大豆油组最高，菜籽油组次之，以下依次为芝麻油组、牛油组、猪油组、棉籽油组；鱼体粗脂肪含量(％)以大豆油组最高， 西南农业大学颀士学位论文菜籽油组次之，以下依次为芝麻油组、猪油组、棉籽油纽、牛油组。②形体指数：不同油脂对奥尼罗非鱼肝胰脏指数、内脏指数影响不显著（P＞0刀5）． （树鱼体腴脂脂肪酸性质的影响：主要表现为鱼体腴脂碘值与所饲油脂的碘值具有玫强的正相关性；比较饲料中油脂的碘值与鱼体腴脂碘值，大豆油组、芝麻油组、菜籽油组、棉籽油组鱼体腹脂碘值低于对应饲料油的碘值，而猪油组、牛油组鱼体腹脂碘值高于对应饲料油的碘值，表明鱼体对从饲料吸收、利’ 0用的脂肪有一定的选择、加工作用． 试验2 必需脂肪酸n－6in3比例对奥尼罗非鱼生长的影响I 以尾均重约32．5克的270尾奥尼罗非鱼鱼种为实验动物，随机分为9个组．以必需脂肪酸n6／n3比例模式、脂肪水平为试验因素，采用二因子3水平的正交设计得到9个试验饲料营养组合．其中n－6／n习的三个比例模式分别为：22．25（A ＃式）、15．45（B模式）、9．04（C ＃式）；脂肪的三个水平为 1％、3％、5％。所制饲料分别饲喂9组试验罗非鱼。经过55天的常规养殖试验，得到如下结果：1．必需脂肪酸n－6／n－3比例的影响 （l）A模式组的罗非鱼日增重率（O）高于 B模式组，但差异不显著（P＞0．05），而A、B模式组罗非鱼日增重率显著高于C模式组（P＜o．05）。 口）A模式组的饲料蛋白效率（％）高于 B模式组，但未达到显著水平 （＊。o＊5），而A、B模式组均显著高于C模式组（P＜0＊5）。 O）鱼体品质：1）鱼体生化组成：①A模式组的鱼体粗蛋白质含量（％）极显著高于B模式组（P＜0．01），而B模式组高于C模式组，但未达到显著水平 （P＞0刀5）；③鱼体粗脂肪含量（％），以A模式组显著高于Bc模式组乃功刀5），而B模式纽高于C模式组，但差异不显著（P＞0二05）；③鱼体水分、灰分、钙、磷含量（叨在各模式组问差异不显著（P＞0．05）。2）鱼体形体指数：①A模式组的鱼体肥满度高于B模式组，但未达显著水平（P＞o刀5），而A、B模式组鱼体肥满度均显著高于C模式组（P＜o刀5）；③鱼体内脏指数以C模式组高于A模式组，A模式组高于B模式组，但均未达显著水平o＞0刀5） K）代谢测定：1）与氨基酸代谢相关的转氨酶活力测定：①三种模式组间，B模式组的鱼体肌肉GOT活力高于C模式组，C模式组高于A模式组，但差 2 必需脂肪酸n－6In．3比例与抽脂水平对臭尼罗非鱼生长的影响 异均不显著（P＞0．05）；③C ＃式组的肝腮脏 GOT活力高于 A＃式组（P＞0．05），更多还原

【Abstract】 Two experiments were conducted to study the effect of EFA n-6/n-3 rate and lipid level on the growth of hybrid tilapia(T.autea ?* T.nilotica ? ).Experiment one: The effect of different dietary lipids on growth, body quality was studied . Hybrid tilapia , about 82.9g per fish , was divided into 6 groups in feeding trial for 35d, to study the ability of utilizing different dietary lipids . The experiment feeds were contained respectively with 3% of cotton oil i linseed oil, soybean oil, rapeseedoil, lard, beef tallow. Accordingly, the groups of tilapia were named group 1, 2, 3, 4, 5, 6.The results were followed:1 The growth result of hybrid tilapia:(l)The difference of daily growth rate was observed: group 2 was the highest, group 3 was the second, group 4 the third, group 1 the fourth, then group 6 , group 5.(2)Different feed efficiency was observed: group 2 was the highest, group 4 the second , group 3 the third, group 1 the fourth, then group 6 , group 5.2 Body quality:l)The biochemisty composition of the body was tested. (1) The body crude protein content (%) was "groups > group 4 > group 2 > group 6 > group 5 > group 1". (2) The body ether extract content (%) was "group 3 > group 4 > group 2 > group 5 > group I > group 6". (3 ) The moisture (67.76-70.48%). ash(2.80~3.56%), calcium (0.68-1.16%). phosphorus(0.36~0.43%) of the body were not significantly affected by dietary lipids. 2)Body fat property was significantly affected by dietary lipid. The body fat iodine value (mg/100g) tended to resemble that of dietary lipid.Experiment two: Using two-factor, three level orthogonal design, 270 hybrid tilapia with an average initial weight of 32.5g, were randomly divided into 9 groups in feeding trial for 64d to study the optimal EFA n-6/n-3 rate pattern and dietary lipid level , discussing a new way to evaluate and modulate dietary lipid nutrition. One factor is n-6/n-3EFA rate pattern : 22.25(patternA) , 15.45(Pattem B) , 9.04(PatternC). The other is dietary lipid level: 5% level, 3% level, 1% level. The growth, metabolism and body quality of hybrid tilapia were studied.The results were following:1 The growth of hybrid tilapia: (1) daily growth rate ( % ): Pattern A > Pattern B( P >0.05 ), and Pattern B > Pattern C ( P <0.05 ) ; 5% level >3% level > 1% level ( P >0.05 ) . (2) feed protein efficiency : Pattern A > Pattern B ( P >0.05) , and Pattern B > Pattern C ( P O.05 ) ; 5% level >3% level > 1% level ( P >0.05) .2 body quality determination: There is no significant difference in body moisture, ash, calcium and phosphorus content except of crude protein, ether extract and body index: (1) body crude protein content: Pattern A > Pattern B ( P<0.05) and Pattern B> Pattern C ( P>0.05 ); 5%level >3% level ( P >0.05)and 3% level > 1% level ( P<0.01 ). (2 )body ether extract content: Pattern A > Pattern B ( P <0.05 ) and Pattern B > Pattern C ( P >0.05 ); 3% level >5% level > 1 % level ( P >0.05 ) . ( 3 ) plumpness: Pattern A > Pattern B ( P >0.05 ) and Pattern B > Pattern C (P<0.05); 3%level>5%level .( P>0.05) and3%level> 1%level (PO.05). (4) internal organ index: Pattern C > Pattern A > Pattern B ( P >0.05) ; 3% level >5% level ( P >0.05) and 5% level > 1 % level ( P O.05 ) .3 Determination of metabolism: 1 ) The determination of transaminase correlating with amino acid metabolism: (1)the glutamic oxalacetic transaminase (GOT) of muscle was "Pattern B>Pattern OPattern A (P>0.05 ) ; 1% level>5% level (P<0.01),5% level>3% level". (2) the GOT of hepatopancreas was "Pattern OPattern A (P>0.05 ), Pattern A>Pattern B (P>0.05 ) and Pattern C>Pattern B( P<0.05); 1% level>5% leveK P<0.01), 5% level>3% leveK P>0.05)". 2) The determination of metabolite of fatty acid : ketone body was "Pattern OPattern B>PatternA (P<0.05) ; 5% level>l% level (P<0.05) , 1 % level>3% level (P>0.05) ".The results indicated that :1 Six kinds of dietary lipid affected the growth, feed efficiency and body quality of the hybrid tilapia. It is determined not only by n-6, n-3 fatty acids更多还原