维生素A对黄鳝生长、转氨酶活性和肝脏显微结构的影响

Effects of Vitamin A on Growth, Transaminase Activity and Liver Microstructure of Monopterus albus

【目的】为探究黄鳝(Monopterus albus)对维生素A的需求量。【方法】通过向基础饲料中添加维生素A醋酸酯,配制出7种等氮等能的试验饲料(实测含量为2 910,3 230,3 520,3 840,5 020,7 030,11 800 IU/kg),编号为L1~L7。随机将1 400尾(2.64±0.03)g的黄鳝分为7组,每组4个重复,每个重复50尾,饲养56 d后,以生长性能、血清转氨酶活性及肝脏显微结构等指标评价黄鳝对维生素A的需求量。【结果】(1)黄鳝的末均重(FBW)、增重率(WGR)及特定生长率(SGR)随饲料维生素A水平的增加呈先上升后下降的趋势,L3组黄鳝FBW、WGR和SGR显著高于L1组(P<0.05),FCR差异不显著(P>0.05)。(2)饲料维生素A对肝体指数、脾体指数和肥满度无显著影响(P>0.05),脾体指数随饲料维生素A水平的升高呈先上升后下降的趋势。(3)血清谷丙转氨酶(GPT)和谷草转氨酶(GOT)随饲料维生素A水平的升高呈现先降低后升高的趋势,L1和L7组血清GPT和GOT活性均显著高于L3~L5(P<0.05)。(4)血清总胆固醇(T-CHO)和甘油三酯(TG)含量随饲料维生素A水平升高呈现先上升后下降的趋势,L5组T-CHO含量显著高于L1、L6和L7组(P<0.05),L3组TG含量最高。(5)L1组黄鳝肝脏细胞肿大,多数细胞核消失,L6和L7组肝细胞出现空泡化。【结论】以WGR为评价指标得出黄鳝适宜维生素A需求量为3 482 IU/kg。综合生长性能、血清转氨酶活性、肝脏显微结构等指标,建议其需求量为3 230~5 020 IU/kg。

[Objective]This study aims to investigate the requirement of vitamin A for Monopterus albus.[Method]Seven isonitrogenous and isoenergetic experimental diets numbered L1-L7(measured contents were2 910,3 230,3 520,3 840,5 020,7 030,11 800 IU/kg)were prepared by adding vitamin A acetate to the basal diet.1 400 M. albus(2.64±0.03 g)were randomly divided into 7 groups with 4 replicates per group and 50 M.albus per replicate.After feeding for 56 days,the vitamin A requirement of M. albus was evaluated by growth performance,serum transaminase activity and liver microstructure.[Result](1)the final average weight(FBW),weight gain rate(WGR)and specific growth rate(SGR)of M. albus increased firstly and then decreased with the increasing of dietary vitamin A level,FBW,WGR and SGR of M. albus in L3 group were significantly higher than those in L1 group(P<0.05),but there was no significant difference in FCR(P>0.05).(2)Dietary vitamin A had no significant effects on hepatosomatic index,splenosomatic index and fatness(P>0.05),and splenosomatic index was firstly increased and then decreased with the increasing of dietary vitamin A level.(3)Serum glutamic-pyruvate transaminase(GPT)and glutamic-oxalacetic transaminase(GOT)were firstly decreased and then increased with the increasing of dietary vitamin A level,and the activities of serum GPT and GOT in L1and L7 groups were significantly higher than those in L3-L5(P<0.05).(4)Serum total cholesterol(T-CHO)content and triglyceride(TG)content were firstly increased and then decreased with the increasing of dietary vitamin A level,the T-CHO content in L5 group was significantly higher than that in L1,L6 and L7 groups(P<0.05),and TG content in L3 group was the highest.(5)The hepatocytes of L1 group were swelling and most of the nuclei disappeared,while the hepatocytes of L6 and L7 groups were vacuolated.[Conclusion]The optimal vitamin A requirement of Monopterus albus is 3 482 IU/kg with WGR as evaluation index.Taking the growth performance,serum transaminase activity and liver microstructure into a comprehensive consideration,the recommended requirement is 3 230-5 020 IU/kg.