仿刺参幼参对维生素A最适需求量

Optimum dietary vitamin A requirement of the juvenile sea cucumber Apostichopus japonicus

为了探讨仿刺参幼参对配合饲料中维生素A(V_(A))的适宜需求量,实验在基础饲料中分别添加维生素A乙酸酯,配制V_(A)含量分别为3250(D1)、5187(D2)、7054(D3)、8970(D4)、12975(D5)和16400(D6)IU/kg的6组等氮等能的实验饲料,饲喂初始体重为(15.48±0.01)g仿刺参幼参8周。结果显示,①V_(A)对仿刺参存活率(SR)无显著影响,显著提高了增重率(WG)和特定生长率(SGR);②V_(A)显著提高了体壁粗脂肪和V_(A)含量,降低了羟脯氨酸含量;③肠道脂肪酶(LPS)活性呈上升趋势,D1组显著低于其他组,淀粉酶(AMY)活性呈先下降后上升的趋势;④肠道谷草转氨酶(AST)、总抗氧化能力(T-SOD)及过氧化氢酶(CAT)活性均呈先升后降趋势,AST及CAT活性均在D4组出现最高值,D2~D5组T-SOD活性显著高于D1组,碱性磷酸酶(AKP)活性呈上升趋势,D1组显著低于其他组,丙二醛(MDA)含量逐渐降低。综上所述,饲料中适宜含量的V_(A)能促进仿刺参生长,提高机体脂肪代谢及抗氧化应激能力;以增重率为评价指标,经一元二次回归分析得出,初始体重为15.48 g的仿刺参对饲料中V_(A)的最适需求量为10000 IU/kg。本实验结果可为仿刺参配合饲料中V_(A)的添加量提供参考,也可为仿刺参“微营养素平衡”配合饲料的开发提供依据。

Sea cucumber Apostichopus japonicus is one of most valuable marine cultured species in northeast China,and the cultured production reached 170000 tons in 2020.With the rapid development of A.japonicus breeding industry,high efficiency and environmental protection formula diet has become one of bottleneck problem which inhibited the development of industry.Vitamin A(V_(A)),also called retinol,is the general name of monounsaturated alcohol or alcohol active substances,which is an extremely important and easily deficient fat soluble vitamin.V_(A) can maintain vision,promote cell differentiation and bone development,and participate in fish mucus secretion and fat metabolism.Meanwhile,it also can improve animal growth rate,reproductive performance and disease resistance of Cyprinus carpio var.Jian and Scophthalmus maximus,but long term excessive intake of V_(A) may result in bone deformities of Sparus aurata.So it is very important to determine the optimum dietary V_(A) in formulate diet.In order to investigate the effects of dietary V_(A) on growth performance,body composition,digestive metabolism and non-specific immunity for A.japonicus juveniles,an 8-week feeding experiment was conducted with A.japonicus juveniles.Six isonitrogen and isoenergetic diets with graded levels V_(A)[3250(D1),5187(D2),7054(D3),8970(D4),12975(D5),16400(D6)IU/kg]were formulated by adding V_(A) acetate into basal diet.Each diet was assigned to triplicate tanks with 30 A.japonicus juveniles with initial body weight(15.48±0.01)g.Results showed that there was no significant effect on survival rate,but both the weight gain rate and specific growth rate were significantly increased.With the increasing of dietary V_(A) levels,the contents of crude lipid and V_(A) of body wall were increased,and crude ash contents increased firstly and thereafter declined.The contents of hydroxyproline were decreased and D1 group was significantly higher than other groups.The activity of lipase was increased with the increasing of dietary V_(A) levels,and D1group was significantly lower than other groups.The activity of amylase was increased first and then decreased afterwards.There were no differences in protease activities among all groups.With the increasing of dietary V_(A) levels,all of the activities of aspartate aminotransferase(AST),total superoxide dismutase(T-SOD)and catalase(CAT)were first elevated and then fell down,and the activities of AST and CAT reached the highest in D4 group.The activity of T-SOD of D3 and D4 groups were significantly higher than other groups.The activity of alkaline phosphatase showed an upward trend and D1 group was significantly lower than other groups.The contents of malondialdehyde were decreased.Taking the weight gain rate as the evaluation index,analysis by a linear regression equation indicated that the optimum dietary V_(A) requirement for A.japonicus(initial body weight 15.41g)was 10000 IU/kg.The results of this experiment can provide a reference for the addition of V_(A) in the formula feed,and also provide a basis for the development of"micronutrient balance"formula feed of A.japonicus.