酵母培养物和芽孢杆菌对凡纳滨对虾生长、蛋白酶活性和免疫性能的影响

研究了饲料中添加酵母培养物(益康XP)和芽孢杆菌(Bacillus)制剂对凡纳滨对虾(Litopenaeusvannamei)生长、肌肉成分、蛋白酶活性和免疫功能的影响。在基础饲料(对照组)中分别添加0.075%益康XP、0.100%益康XP、0.200%芽孢杆菌,饲养均重(5.57±0.21)g的凡纳滨对虾45 d。结果表明,添加0.075%益康XP、0.100%益康XP、0.200%芽孢杆菌分别提高凡纳滨对虾增重率17.24%、12.29%、20.18%,降低饲料系数14.28%、9.77%、12.03%,提高蛋白质效率16.49%、10.05%、12.98%(P<0.05);添加酵母培养物和芽孢杆菌对凡纳滨对虾肌肉组成成分没有影响(P>0.05);0.075%益康XP组、0.100%益康XP组、0.200%芽孢杆菌组肝胰脏蛋白酶活性较对照组分别提高25.24%、15.22%、54.92%(P<0.05);各试验组肠蛋白酶活性与对照组相比有所提高,但均未达到显著水平(P>0.05);0.100%益康XP、0.200%芽孢杆菌组凡纳滨对虾血清酚氧化酶活性、溶菌酶活性和超氧化物歧化酶活性均显著高于对照组(P<0.05);攻毒实验表明,感染溶藻弧菌后,芽孢杆菌组对虾第1、3、4天的累积死亡率均显著低于对照组(P<0.05),第4天时的免疫保护率达到27.1%,而添加益康XP对累积死亡率无显著影响(P>0.05)。综上所述,饲料中添加酵母培养物益康XP和芽孢杆菌均能改善凡纳滨对虾生长性能和消化功能,芽孢杆菌能增强凡纳滨对虾对溶藻弧菌的抗感染功能。

Effects of yeast culture and Bacillus on growth, protease activity and immunity of Litopenaeus vannamei

A feeding experiment was conducted to investigate the effects of yeast culture and Bacillus on growth performance,protease activity and immunity of Litopenaeus vannamei.Four experimental diets were formulated by adding yeast culture(Yikang XP) and Bacillus in basal diet(control diet): 0.075% Yikang XP,0.100% Yikang XP,0.200% Bacillus.Shrimps with initial body weight of 5.57±0.21g were fed for 45 days.Results showed that weight gains(WG) increased by 17.24%,12.29%,20.18%,feed conversion ratio(FCR) decreased by 14.28%,9.77%,12.03% and protein efficiency ratio(PER) increased by 16.49%,10.05%,12.98% respectively by the addition of 0.075% Yikang XP,0.100% Yikang XP,0.200% Bacillus in diet compared with the control group(P< 0.05);No differences were observed in muscle composition among treatments(P>0.05);Hepatopancreas protease activity in 0.075% Yikang XP,0.100% Yikang XP,0.200% Bacillus group was 25.24%,15.22%,54.92% higher than that of control group respectively(P<0.05),while intestinal protease activity presented weak increase(P>0.05);The activity of serum phenoloxidase(PO),lysozyme(LZM) and superoxide dismutase(SOD)in 0.100% Yikang XP and 0.200% Bacillus group was all significantly higher than that of the control group(P<0.05);In the challenge trial,no significant difference was found in accumulative mortalities between the control group and Yikang XP groups(P>0.05),while accumulative mortality in Bacillus group was significantly lower than the control group on 1st,3rd and 4th day after injection of Vibrio alginolyticus(P<0.05).Relative survival percent of 0.200% Bacillus group reached 27.1% on the 4th day after injection of V.alginolyticus.Results showed that dietary yeast culture and Bacillus could improve growth performance and digestive function of L.vannamei,and Bacillus have obvious benificial effects on immunity function and resistence of L.vannamei to V.alginolyticus.