饲料中蛋白质和脂肪水平对胭脂鱼生长性能及体组成的影响

摘要

A 3 × 3 factorial design was adopted in this experiment to investigate the effects of dietary protein and lipid levels on growth performance and body composition of Chinese sucker ( Myxocyprinus Asiaticus) , in or-der to determine the optimum dietary protein and lipid levels of Chinese sucker. Nine experimental diets were prepared with three protein levels ( 35%, 40% and 45%) and three lipid levels ( 6%, 8% and 10%) , and Chinese sucker with the average body weight of (16.40±0.02) g were fed the 9 kinds of diets for 8 weeks. Each diet was randomly fed three cement pool, and each cement pool had 30 fish. The results showed that weight gain rate ( WGR) , specific growth rate ( SGR) , feed conversion ratio( FCR) and protein efficiency ra-tio (PER)were significantly influenced by both dietary protein and lipid levels (P<0.05), but there were no interactions between dietary protein and lipid levels existed for above indices ( P>0.05) . The WGR, SGR and PER in 35% protein group were significantly lower than those in 40% and 45% protein groups ( P<0.05) , but the FCR had an opposite trend of changing. The WGR and SGR in 6% lipid group were significantly lower than those in 8% and 10% lipid groups ( P<0.05) , and the FCR in 6% and 8% lipid groups was significantly higher than that in 10% lipid group (P<0.05), but the PER had an opposite trend with FCR. Crude protein and crude lipid contents in whole-body improved significantly ( P<0.05) as protein level increased from 35%to 40%. Contrary to moisture content, crude lipid content in whole-body increased with increasing lipid level. Dietary protein level had significant influences on valine, isoleucine, histidine, glutamic acid, essential amino acids and total amino acid contents in whole-body ( P<0.05) , and dietary protein level had a significant influ-ence on whole-body arginine content only ( P<0.05) . Both dietary protein and lipid levels had little influence on the whole-body fatty acid composition of Chinese sucker, only C14:0 and C18:0 contents in whole-body were changed to some extent. The results indicate that the optimum dietary protein and lipid levels of Chinese sucker are 40% and 6% to 8%, respectively.%本试验采用3×3因子设计,通过探讨饲料中蛋白质和脂肪水平对胭脂鱼生长性能及体组成的影响,确定胭脂鱼饲料中蛋白质和脂肪的适宜水平. 试验设计3 个蛋白质水平( 35%、40%和45%)和3个脂肪水平(6%、8%和10%),共配制9种试验饲料,饲喂平均体重为(16.40± 0.02) g的胭脂鱼幼鱼8周. 每种试验饲料随机饲喂3个水泥池,每个水泥池放养胭脂鱼幼鱼30尾. 结果表明:饲料中蛋白质和脂肪水平对胭脂鱼的增重率、特定生长率、饲料系数和蛋白质效率均有显著影响(P<0.05),但二者对上述指标无显著的交互作用(P>0.05). 35%蛋白质组的增重率、特定生长率和蛋白质效率显著低于40%和45%蛋白质组( P<0.05) ,而饲料系数的变化趋势则相反. 6%脂肪组的增重率和特定生长率均显著低于8%和10%脂肪组( P<0.05) ,6%和8%脂肪组的饲料系数显著高于10%脂肪组( P<0.05) ,而蛋白质效率则与饲料系数的变化趋势相反. 当饲料蛋白质水平从35%提高到40%时,全鱼的粗蛋白质和粗脂肪含量显著上升( P<0.05);饲料脂肪水平越高,全鱼粗脂肪含量越高,全鱼水分含量则相反. 饲料中蛋白质水平显著影响全鱼缬氨酸、异亮氨酸、组氨酸、谷氨酸、必需氨基酸以及总氨基酸含量(P<0.05),饲料中脂肪水平仅显著影响全鱼精氨酸含量( P<0.05). 饲料中蛋白质和脂肪水平对胭脂鱼全鱼脂肪酸组成的影响较小,仅观察到全鱼饱和脂肪酸中的C14:0和C18:0含量有一定的变化. 由结果可知,胭脂鱼饲料中适宜的蛋白质和脂肪水平分别为40%和6%~8%.