不同糖脂比饲料对大规格草鱼生长性能和形体指标的影响

Effects of Different Dietary Carbohydrate Lipid Ratios on Growth Performance and Morphometric Parameters of Large-sized Grass Carp(Ctenopharyngodon idellu)

研究旨在探究草鱼膨化饲料中不同糖脂比(CHO:L)对大规格草鱼[(1061.33±12.49)g]生长性能和形体指标的影响。试验设计了4个等氮(粗蛋白30%)等能(12.5 kJ/g)不同糖脂比处理组(30%小麦、1.4%豆油,糖脂比6.49组;25%小麦、2.4%豆油,糖脂比4.94组;19%小麦、4.1%豆油,糖脂比3.42组;14%小麦、5.8%豆油,糖脂比1.93组)和等氮(粗蛋白30%)略低能量(11.5 kJ/g)的(14%小麦、3%豆油,糖脂比3.11组)试验组,共5个试验组,每组5个重复,每个重复放置25尾鱼,并进行60 d的养殖试验。结果表明,在相同可消化能水平下,随着饲料中糖脂比例不断降低,草鱼的增重率、特定生长率、肥满度不断升高,饲料系数下降,并在糖脂比1.93组,草鱼的增重率、特定生长率、饲料系数和肥满度达到最高,说明饲料能量分配在脂肪上比较与分配在糖类上更有助于该规格草鱼的生长;在相同的可消化能(12.5 kJ/g)水平下,不同糖脂分配对草鱼的肝体比和成活率没有显著的影响。1000 g左右草鱼对饲料脂肪的利用率高于淀粉。研究表明,同样的可消化能水平下,能量分配在脂肪上比分配在淀粉上更有助于草鱼的生长;从糖脂比3.42组和糖脂比1.93组的生长结果比较来看,豆油小麦在草鱼上的比价关系:1%的豆油相当于3%的小麦。

A 60-days feeding experiment was conducted to investigate the effects of different dietary carbohydrate lipid ratios on growth performance and morphometric parameters of grass carp(Ctenopharyngodon idellu).Four isonitrogenous and isoenergy(12.5 kJ/g)diets were formulated design with carbohydrate lipid(CHO:L)ratios of 6.49(wheat 30%,soybean oil 1.4%),4.94(wheat 25%,soybean oil 2.4%),3.42(wheat 19%,soybean oil 4.1%),1.93(wheat 14%,soybean oil 5.8%),and one isonitrogenous and lower energy(11.5 kJ/g)was formulated design to CHO:L ratio=3.11(wheat 14%,soybean oil 5.8%),respectively.Each diet was fed to 5 replicates with 25 grass carp[initial body weight=(1061.33±12.49)g]in each replicate.The results showed that in the same digestible energy level different dietary carbohydrate lipid ratios significantly affected the weight gain(WG),specific growth rate(SGR)and condition factor(CF).The WG,SGR and CF decreased with the increasing of lipid and the decreasing of starch.And the group fed with CHO:L=1.93(wheat 14%,soybean oil 5.8%)was the highest.This indicated that the feed energy distribution on lipid was more conducive to the growth of grass carp than on carbohydrate.The hepatosomatic index(HIS)and survival rate(SR)were similar among the treatments.The results showed that medium size grass carp(about 1000 g)showed higher feed utilization at lipid than that of the starch.In conclusion,in the same digestible energy level,the distribution of energy on lipid was more conducive to grass carp growth than that on carbohydrate.Compared with the growth performance results of group CHO:L=3.42 and CHO:L=1.93,the price relation of soybean oil and wheat on grass carp was as the followsing:1%soybean oil was equivalent to 3%wheat.