柠檬酸对异育银鲫生长及营养物质消化率的影响

进行了两个试验以考察在饲料中添加柠檬酸对异育银鲫生长及营养物质消化率的影响。试验一采用420尾平均体重为6．5g的异育银鲫鱼种，在基础饲料（对照组）中分别添加0．1％、0．2％、0．3％柠檬酸，经21 dN养后，各组增重率分别为53．4％，56．9％，59．0％，57．8％，其中添加0．2％柠檬酸显著提高了异育银鲫增重率（P〈0．05）。试验二采用150尾平均体重为45．0g的异育银鲫，在基础饲料（对照组）中分别添加0．1％、0．2％、0．3％、0．4％柠檬酸，进行了两周的消化试验。结果表明，添加0．1％、0．2％柠檬酸显著提高了磷消化率（P〈0．05），添加0．2％柠檬酸显著提高了干物质消化率（P〈0．05），但添加柠檬酸对蛋白质消化率没有显著影响（P〉0．05）。上述研究表明，饲料中添加适宜剂量柠掾酸可促进异育银鲫生长，提高异育银鲫对饲料干物质和磷的消化率，柠檬酸的适宜添加量为0．2％。

Effects of citric acid on growing performance and nutrients digestibility of allogynogenetic crucian carp

Two experiments were conducted to investigate the effects of adding citric acid on growing performance and digestibility of allogynogenetic crucian carp.In experiment 1,420 healthy fish with an average weight of 6.5 g,were separated randomly into 5 groups and fed with 0.0%(control),0.1%,0.2%,0.3% citric acid addition for 21 days,the growth rate was 53.4%,56.9%,59.0%,57.8%,respectively.The growth rate was significantly improved by 0.2% addition(P<0.05).In experiment 2,150 healthy fish with average weight of 45.0 g were separated randomly into 5 groups and fed the diet with 0.0%(control),0.1%,0.2%,0.3%,0.4% citric acid addition for two weeks to measure nutrients digestibility.The results showed that phosphorus(P) digestibility was significantly improved by 0.1% or 0.2% citric acid addition and dry material(DM) digestibility only by 0.2% citric acid addition(P<0.05).Adding citric acid in diet had no effect on protein digestibility.Results above showed that adding proper level of citric acid could promote the growing performance and P,DM digestibility for allogynogenetic crucian carp,and the appropriate level of citric acid addition is 0.2%.