饲料维生素A水平对黄鳝生长性能、血清生化指标和组织消化酶活性的影响

Effects of Dietary Vitamin A Level on Growth Performance,Serum Biochemical Indices and Tissue Digestive Enzyme Activities of Monopterus albus

本试验旨在研究黄鳝对饲料维生素A的需求量,以期为黄鳝人工配合饲料的配制提供理论依据。将体重为(7.32±0.02) g的人工黄鳝1 260尾随机分为7组,每组4个重复,每个重复45尾,分别投喂7种不同维生素A水平(实测:3 201、3 620、4 010、4 730、6 510、9 720和16 890 IU/kg,记作L1~L7)的等氮等能饲料,试验期70 d。结果表明:黄鳝末均重(FBW)、增重率(WGR)和特定生长率(SGR)随饲料维生素A水平的升高呈先升高后下降的趋势,L2、L3和L4组FBW、WGR和SGR显著高于L1、L7组(P<0.05)。黄鳝血清谷草转氨酶(GOT)、谷丙转氨酶(GPT)活性随饲料维生素A水平的升高呈先下降后上升的趋势,L4组活性显著低于L1、L7组(P<0.05)。血清甘油三酯(TG)、总胆固醇(T-CHO)含量组间差异显著(P<0.05),且L5组含量最高;L3~L5组肝脏TG和T-CHO含量显著降低(P<0.05)。L3~L5组血清葡萄糖(GLU)含量均显著高于其余各组(P<0.05),L7组血清GLU含量最低。组织中蛋白酶和脂肪酶活性均随饲料维生素A水平升高呈先上升后下降的趋势,其中L3组肝胰脏、胃和前肠蛋白酶活性最高,L3组胃脂肪酶活性最高,L5组肝胰脏和前肠脂肪酶活性达到最高。综上所述,饲料适宜维生素A水平可提高黄鳝组织蛋白酶和脂肪酶活性,促进黄鳝生长;通过折线回归分析饲料维生素A水平与WGR的关系,得出黄鳝饲料中维生素A适宜水平为3 810 IU/kg。

This experiment was conducted to study the dietary vitamin A requirement of Monopterus albus in order to provide theoretical basis for the preparation of artificial compound feed for M. albus. A total of 1 260young M. albus with an average body mass of(7.32±0.02)g were randomly divided into 7 groups,with 4replicates in each group,and 45 M.albus in each replicate. The M. albus seedlings were fed 7 isonitrogenous and isoenergetic diets with different vitamin A levels(measured values:3 201,3 620,4 010,4 730,6 510,9 720 and 16 890 IU/kg,labeled L1 to L7),and the experiment lasted for 70 days. Results showed as follows:final average weight(FBW),weight gain rate(WGR)and specific growth rate(SGR)of M. albus increased first and then decreased with the increase of dietary vitamin A level,FBW,WGR and SGR in L2,L3and L4 groups were significantly higher than those in L1 and L7 groups(P<0.05). With the increase of vitamin A level,the activities of glutamic oxalacetic transaminase(GOT)and alanine aminotransferase(GPT)in serum of M. albus were firstly decreased and then increased,and the activities in the L4 group were significantly lower than those in L1 and L7 groups(P<0.05). The contents of serum triglyceride(TG)and total cholesterol(T-CHO)were significantly different(P<0.05),and the content in L5 group was the highest. The contents of liver TG and T-CHO in L3 to L5 groups decreased significantly(P<0.05). The content of serum glucose(GLU)in L3 to L5 groups was significantly higher than that in other groups(P<0.05),and the content of serum GLU in L7 group was the lowest. The protease and lipase activities increased firstly and then decreased with the dietary vitamin A level increasing,and the protease activities in hepatopancreas,stomach and foregut in the L3 group were the highest,the lipase activities in stomach lipase in L3 group were the highest,and the lipase activities in hepatopancreas and foregut in L5 group were the highest. Appropriate vitamin A level in diets can improve the activities of protease and lipase of M. albus and promote the growth of M. albus.The optimal level of vitamin A is 3 810.43 IU/kg by cracked line analysis of the relationship between vitamin A level and WGR.[Chinese Journal of Animal Nutrition,2022,34(5):3208-3219]