草鱼幼鱼对饲料中核黄素的需要量

Dietary Riboflavin Requirement of Juvenile Grass Carp(Ctenopharyngodon idellus)

配制核黄素含量分别为0.54、2.32、4.08、5.78、9.28和19.35 mg/kg的6种纯化饲料,投喂初始均重为(11.21±0.16)g的草鱼幼鱼8周,通过研究核黄素对其生长性能、肝胰脏中D-氨基酸氧化酶(D-AAO)与肠道中消化酶活力及体成分的影响,以确定草鱼幼鱼对饲料中核黄素的需要量。每种饲料设3个重复,每个重复放养20尾鱼。结果表明:0.54和2.32 mg/kg组草鱼幼鱼的成活率显著低于其他各组(P<0.05);随着饲料中核黄素含量的增加,草鱼幼鱼的增重率、特定生长率、饲料效率、肝胰脏中D-AAO及肠道中消化酶活力均先升高后趋于稳定,当饲料中核黄素含量为5.78 mg/kg时,以上指标均达到最大值;5.78 mg/kg组的肝体比显著高于0.54 mg/kg组(P<0.05),但饲料中核黄素含量对脏体比、肥满度及全鱼的水分、粗蛋白质、粗脂肪和粗灰分含量无显著影响(P>0.05)。折线模型回归分析表明,草鱼幼鱼获得最佳生长时对饲料中核黄素的需要量为5.54 mg/kg;肝胰脏中D-AAO活力达到最佳时对饲料中核黄素的需要量为5.99 mg/kg。

A feeding trial was carried out to estimate the dietary riboflavin requirement of juvenile grass carp（Ctenopharyngodon idellus） based on growth performance,hepatopancreas D-amino acid oxidase（D-AAO）and intestinal digestive enzyme activities and body composition.Six purified diets were formulated to contain0.56,2.32,4.08,5.78,9.28 and 19.35 mg/kg riboflavin,respectively.Juvenile grass carp with an average initial body weight of（11.21±0.16） g were fed the diets for 8 weeks,and each diet had 3 replicates with 20 fish per replicate.The results showed as follows：survival rate in 0.56 and 2.32 mg/kg groups was significantly lower than that in other groups（P〈0.05）.Weight gain rate（WGR）,specific growth rate（SGR）,feed efficiency rate（FER）,hepatopancreas D-AAO and intestinal digestive enzyme activities of fish were firstly increased and then seemed to stabilize with increasing dietary riboflavin content,and the biggest values of them appeared when dietary riboflavin content was 5.78 mg/kg.Hepatosomatic index（HSI） in 5.78 mg/kg group was significantly higher than that in 0.54 mg/kg group（P〈0.05）.Viscerasomatic index（VSI）,condition factor（CF） and the contents of whole body moisture,crude protein,crude lipid and ash were not significantly affected by dietary riboflavin content（P〉0.05）.Broken line regression analysis shows that dietary riboflavin requirement of juvenile grass carp with the best growth and hepatopancreas D-AAO activity is 5.54 and5.99 mg/kg,respectively.