氨基酸微量元素螯合物对草鱼生长性能、血清生化指标及微量元素沉积的影响

Effects of Amino Acid Trace Element Chelates on Growth Performance,Serum Biochemical Indexes,and Trace Element Deposition of Grass Carp(Ctenopharyngodon idellus)

为研究饲料中添加氨基酸微量元素螯合物对草鱼(Ctenopharyngodon idellus)生长性能、微量元素沉积及血清生化指标的影响,本试验以初始体重为(40.05±0.05)g的草鱼为研究对象,共计720尾随机分为6组,对照组(CON组)饲喂不添加微量元素的基础饲料,无机微量元素添加组(IT100组)饲喂在基础饲料中添加草鱼微量元素需要量的100%无机微量元素铜、铁、锌、锰的试验饲料,氨基酸微量元素螯合物添加组(OT25组、OT50组、OT75组和OT100组)饲喂以25%、50%、75%和100%氨基酸微量元素螯合物等比例替代IT100组饲料中无机微量元素的试验饲料,每组3个重复,每个重复40尾鱼,养殖8周。结果表明:1)不同组之间草鱼的存活率、肥满度、肝体比和脏体比没有显著差异(P>0.05)。与CON组相比,IT100组、OT75组增重率显著升高(P<0.05),而饲料系数的变化趋势则与之相反,OT50组和OT75组显著降低(P<0.05)。2)与CON组相比,IT100组、OT50组、OT75组、OT100组肠道胰蛋白酶、淀粉酶和脂肪酶活性均显著升高(P<0.05),OT25组肠道的淀粉酶活性显著升高(P<0.05)。3)根据草鱼脊椎骨微量元素沉积量的二次回归方程,氨基酸微量元素螯合物内元素分别在添加水平为铜67.53%、铁58.22%、锌58.68%、锰56.07%时到达100%无机微量元素效价。4)与CON组相比,IT100组的血清中总胆固醇、低密度脂蛋白胆固醇、尿素氮含量及谷丙转氨酶、谷草转氨酶活性显著降低(P<0.05),血清补体3、高密度脂蛋白胆固醇含量和碱性磷酸酶活显著降低(P<0.05)。与CON组比较,OT各组血清甘油三酯含量均显著降低(P<0.05),OT100组血清总胆固醇、尿素氮含量及谷丙转氨酶活性显著降低(P<0.05),OT75组和OT100组血清低密度脂蛋白胆固醇含量和谷草转氨酶活性显著降低(P<0.05),OT100组血清碱性磷酸酶活性显著上升(P<0.05)。综上所述,饲料中添加适宜比例的氨基酸微量元素螯合物能提高草鱼生长性能、营养消化吸收和脊椎骨内微量元素沉积,其中75%的氨基酸微量元素螯合物替代比例为最适替代比例。

In order to study the effects of amino acid trace element chelates on the growth performance,trace element deposition and serum biochemical indexes of grass carp,a total of 720 grass carp with an initial body weight of(40.05±0.05)g were randomly divided into 6 groups.The control group(CON group)was fed a basal diet without trace elements,and the inorganic trace element addition group(IT100 group)was fed a basal diet supplemented with 100%inorganic trace elements copper,iron,zinc and manganese required by grass carp trace elements.The fish in the amino acid trace element chelate addition groups(OT25,OT50,OT75 and OT100 groups)were fed the experimental diets in which 25%,50%,75%and 100%amino acid trace element chelates were used to replace the inorganic trace elements in the diet of the IT100 group in equal proportions,with 3 replicates in each group and 40 fish in each replicate.The fish were fed for 8 weeks.Results showed as follows:1)there was no significant difference in survival rate,condition factor,liverbody ratio and visceralbody ratio among different groups(P>0.05).Compared with the CON group,the weight gain rate in the IT100 group and the OT75 group was significantly increased(P<0.05),while the change trend of the feed coefficient was opposite;the OT50 group and the OT75 group were significantly lower than the CON group(P<0.05).2)Compared with CON group,the activities of trypsin,amylase and lipase in IT100 group,OT50 group,OT75 group and OT100 group were significantly increased(P<0.05),and the amylase activity in OT25 group was significantly increased(P<0.05).3)According to the quadratic regression equations for trace element deposition in grass carp vertebrae,the efficacy of amino acid trace element chelates reached 100%of that of inorganic trace elements when the addition levels were Cu 67.53%,Fe 58.22%,Zn 58.68%and Mn 56.07%.4)Compared with the CON group,the contents of serum total cholesterol,low density lipoprotein cholesterol,urea nitrogen and the activities of alanine aminotransferase and aspartate aminotransferase in the IT100 group were significantly decreased(P<0.05),and the serum contents of complement 3,high density lipoprotein cholesterol and alkaline phosphatase were significantly decreased(P<0.05).Compared with the CON group,the serum triglyceride content in OT groups was significantly decreased(P<0.05),the serum total cholesterol,urea nitrogen content and alanine aminotransferase activity were significantly decreased in OT100 group(P<0.05),the low density lipoprotein cholesterol content and aspartate aminotransferase activity were significantly decreased in OT75 and OT100 groups(P<0.05),and the alkaline phosphatase activity was significantly increased in OT100 group(P<0.05).In conclusion,the appropriate substitution of amino acid trace element chelates for inorganic trace elements in feed can improve the growth,digestion and absorption,as well as trace element deposition in the vertebrae of grass carp.Among them,75%amino acid trace element chelate substitution ratio was the optimal substitution ratio.