3种不同添加物对凡纳滨对虾生长、非特异免疫和抗病力的影响

Effects of Three Additives on Growth Performance,Non-Specific Immunity and Disease Resistance of Litopenaeus vannamei

为评估3种不同添加物对凡纳滨对虾(Litopenaeus vannamei)生长性能、非特异免疫反应及抗病力的影响,在基础饲料中分别添加了丁酸梭菌CBG01(Clostridium butyricum CBG01)活菌(CB组)、3%聚β-羟基丁酸酯(PHB组)和1%丁酸钠(BS组)来投喂对虾,对照组投喂基础饲料,养殖6周后测量对虾生长情况、检测血清非特异免疫指标和肝胰腺免疫相关基因表达水平,进行副溶血弧菌(Vibrio parahaemolyticus)攻毒实验。研究表明,CB组和PHB组对虾末体质量和特定生长率显著高于对照组(P<0.05),CB组最高,BS组与对照组差异不显著(P>0.05)。3个处理组对虾成活率和饲料效率均显著高于对照组(P<0.05)。3个处理组对虾血清中溶菌酶、过氧化物酶、超氧化物歧化酶活性以及总抗氧化能力显著高于对照组(P<0.05),CB组对虾血清中碱性磷酸酶、酸性磷酸酶、酚氧化酶活性显著高于对照组(P<0.05),PHB组对虾血清中碱性磷酸酶、酸性磷酸酶、总一氧化氮合酶活性显著高于对照组(P<0.05),BS组对虾血清中酸性磷酸酶活性显著高于对照组(P<0.05)。与对照组相比,CB组对虾肝胰腺中所有免疫相关基因(SOD、LZM、proPO、LGBP、HSP70、Imd、Toll、Relish、TOR、4E-BP、eIF4E1α、eIF4E2)相对表达量均显著上调(P<0.05),而PHB组的Toll基因以及BS组的Imd、Toll、Relish、eIF4E2基因相对表达量与对照组无显著差异(P>0.05)。副溶血弧菌攻毒实验表明,3个处理组对虾的累积死亡率均显著低于对照组(P<0.05)。研究结果表明,饲料中添加丁酸梭菌、PHB和丁酸钠均可不同程度地提高凡纳滨对虾的生长性能和非特异免疫能力,能够显著提高对虾对副溶血弧菌感染的抵抗力。总体比较,添加丁酸梭菌和PHB的作用效果基本相当,在一定程度上要优于添加丁酸钠。在饲料生产加工过程中,在难以添加丁酸梭菌活菌的情况下,建议适当添加聚β-羟基丁酸酯来替代丁酸梭菌。

An experiment was conducted to study the effects of three additives on the growth performance,non-specific immunity and disease resistance of Litopenaeus vannamei.Shrimp were fed with live cells of Clostridium butyricum CBG01(CB group),3%poly-β-hydroxybutyrate(PHB group)and 1%sodium butyrate(BS group)in the basal diets,respectively.The basal diet without additives was used as the control group and the feeding trial lasted for 6 weeks.After feeding trial,the final bodyweight,the non-specific immune parameters in the serum and the relative expression levels of immune-related genes in the hepatopancreas of shrimp were measured.Meanwhile,a Vibrio parahaemolyticus challenge experiment was carried out.Results indicated that the final weight and specific growth rate of shrimp in the CB and PHB groups were significantly improved as compared to the control(P<0.05),especially in the CB group.There was no significant difference between the BS and control groups(P>0.05).The survival rate and feed efficiency of three treatment groups were significantly higher than those of the control group(P<0.05).The activities of lysozyme(LZM),peroxidase(POD),superoxide dismutase(SOD)and total antioxidant capacity(T-AOC)in serum of shrimp of three treatment groups were significantly higher than those of the control group(P<0.05).The activities of alkaline phosphatase(AKP),acid phosphatase(ACP)and phenol oxidase(PO)in serum of the CB group,the activities of AKP,ACP and total nitric oxide synthase(T-NOS)in serum of the PHB group and ACP activity in serum of the BS group were significantly higher than those of the control group(P<0.05).Compared with the control group,the relative expression levels of all immune-related genes(SOD,LZM,proPO,LGBP,HSP70,Imd,Toll,Relish,TOR,4E-BP,eIF4E1α,eIF4E2)in the hepatopancreas of shrimp of the CB group were significantly higher than those of the control group(P<0.05).However,the relative expression levels of Toll gene in the PHB group and Imd,Toll,Relish,eIF4E2 genes in the BS group were not significantly different from those in the control group(P>0.05).The challenge test of V.parahaemolyticus showed that the cumulative mortalities of shrimp in three treatment groups were significantly lower than that in the control group(P<0.05).The results showed that dietary addition of C.butyricum,PHB and sodium butyrate improved the growth performance and non-specific immunity capacity to varying degrees and significantly enhanced the resistance of L.vannamei against V.parahaemolyticus.By comprehensive comparisons,the effects of adding C.butyricum and PHB were basically comparable and to some extent superior to the addition of sodium butyrate.When it is difficult to add live cells of C.butyricum in feed production and processing,it is suggested that appropriately added poly-β-hydroxybutyrate may substitute C.butyricum.