棉子糖对花鲈生长、免疫抗应激及抵御嗜水气单胞菌攻毒的影响

EFFECTS OF RAFFINOSE ON GROWTH PERFORMANCE,IMMUNITY,STRESS RESPONSE AND SURVIVAL OF JAPANESE SEABASS(LATEOLABRAX JAPONICUS)CHALLENGED WITH AEROMONAS HYDROPHILA

实验研究了棉子糖对花鲈(Lateolabrax japonicus)生长、非特异性免疫、抗应激能力和嗜水气单胞菌攻毒后存活率的影响。基础饲料依据花鲈营养需求配制。实验设计5个处理,棉子糖添加量分别为:0(对照组)、200、400、800和2000 mg/kg饲料,分别命名为R0、R200、R400、R800和R2000。每个处理3个重复,每个重复30尾鱼(初始体重3 g左右)。实验共持续16周,实验结束后称重并取血清样品用于测定免疫和抗氧化指标。此外还分别进行了30s空气暴露应激和嗜水气单胞菌攻毒实验。结果表明各实验组花鲈存活率和摄食率没有显著差异(P>0.05),R800组增重率显著高于对照组、R400和R2000组(P<0.05)。R400组饲料系数显著高于R800组、蛋白质效率显著低于R800组(P<0.05),但与其他各组没有显著差异。各组间蛋白质沉积率、肝指数没有显著差异(P>0.05),对照组、R200和R2000肥满度显著高于R400和R800组(P<0.05),R800组花鲈内脏比显著低于R400组(P<0.05)。各组间血清溶菌酶、超氧化物歧化酶活力和氧化产物丙二醛含量没有差异(P>0.05)。30s空气暴露应激后血清葡萄糖和皮质醇也未显示差异,但嗜水气单胞菌(Aeromonas hydrophila)攻毒后对照组累计存活率为65%,显著低于各试验组(P<0.05)。棉子糖在花鲈饲料里适宜添加量为800 mg/kg。

A 16w growth trial was conducted to study the effects of raffinose on growth performance,non-specific immunity,stress response and survival of Japanese seabass（Lateolabrax japonicus） challenged with pathogenic bacteria,Aeromonas hydrophila in a recirculation system.Five experimental diets with 0,200,400,800 and 2000 mg/kg of raffinose supplements were prepared,and named as R0,R200,R400,R800 and R2000,respectively.Each diet was fed to triplicates groups of Japanese seabass（initial body weight：average of 3g）,with 30 fish in each tank.At the end of trial,fish were weighed and serum sample were collected.Besides,a 30s air-exposure stress test and a challenge test with A.hydrophila were carried out.Survival and feed intake of fish did not show significant difference among all groups（P0.05）.Weight gain rate（WGR） of R800 group was significantly higher than that of control,R400 and R2000 groups（P0.05）.Feed Conversion Ratio（FCR） and protein efficiency rate（PER） of R800 treatment were significantly lower and higher than R400 treatment,respectively（P0.05）.Condition factor（CF） of control,R200 and R2000 treatments were significantly higher than R400 and R800 treatments（P0.05）.There were no difference on serum lysozyme,superoxide dismutase and malondialdehyde（P0.05）,and glucose and cortisol level of serum after 30s air stress were no difference（P0.05）,either.However,accumulative survival of control group significantly lower than that of groups with various level of raffinose after being challenged by Aeromonas hydrophila（P0.05）.800mg/kg of raffinose was recommended to use in diet of Japanese sea bass.