凝结芽孢杆菌对奥尼罗非鱼消化酶活性、消化率及生长性能的影响

在基础饲料中分别添加不同剂量的凝结芽孢杆菌(Ⅰ:1.0×1011cfu/kg饲料,Ⅱ:3.0×1011cfu/kg饲料,Ⅲ:6.0×1011cfu/kg),室外水族箱中饲养奥尼罗非鱼(Oreochromis niloticus×O.aureus)(34.50±0.25 g),用基础饲料投喂作为对照,每饲料组设三个重复,每水族箱随机放养16尾鱼,投喂率为3%。采用静水饲养以避免各箱之间水的交换。56 d后测定鱼体的生长和消化酶活性。结果显示:不同添加量的凝结芽孢杆菌均能显著提高奥尼罗非鱼胃、肝胰脏和肠道蛋白酶活性(P<0.05),但酶的活性随添加量的提高呈下降趋势。凝结芽孢杆菌的添加对胃、肝胰脏和肠道淀粉酶及脂肪酶活性没有显著影响(P>0.05)。Ⅰ组和Ⅱ组的干物质表观消化率、蛋白质消化率、相对增重率、饵料系数和蛋白质效率均显著高于对照组(P<0.05),而Ⅲ组和对照组之间差异不显著(P>0.05)。结果提示,饲料中添加1.0×1011cfu/kg饲料的凝结芽孢杆菌就能显著促进奥尼罗非鱼的生长和饲料营养物质的利用,满足最佳生长。

Effects of Bacillus coagulans on Digestive Enzyme Activities,Digestibility and Growth Performance of Hybrid Tilapia(Oreochromis niloticus×O.aureus)

In order to examine the effects of supplementing Bacillus coagulans in the diet on growth,digestive enzymatic activities of hybrid tilapia Oreochromis niloticus×O.aureus(initial weight of 34.50±0.25 g),different dosages of B.coagulans,were tested in a 56-day trial.The basal diet was applied as control,in which 1.0×1011 cfu/kg feed,3.0×1011cfu/kg feed,6.0×1011cfu/kg feed of B.coagulans were added into basal diets as test diets,respectively.Triplicate groups were made for each diet and 16 fish were stocked randomly in each tank.Feeding rate was 3%.Each diet was fed to triplicate tanks three times a day.Protease and amylase in the stomach,intestine and hepatopancreas,weight gain rate,feed coefficient,protein efficient rate,hepatosomatic index,were measured.The results showed that the activity of protease in the stomach,intestine and hepatopancreas of fish fed with B.coagulans at different levels in the diet were all significantly higher than control group.No significant difference was observed on the activities of amylase and lipase in the stomach,intestine and hepatopancreas in all groups.Significantly higher(P<0.05)weight gain rate,feed coefficient and protein efficient rate were observed in the fish fed diets with 1.0×1011cfu/kg feed and 3.0×1011 cfu/kg feed of B.coagulans,the difference between the basal diet and diet with 6.0×1011 cfu/kg feed of Bacillus coagulans was not significant(P>0.05).The results suggested that diet with 1.0×1011cfu/kg feed of B.coagulans supplement could significantly promote the growth of tilapia Oreochromis niloticus×O.aureus and the use of feed nutrients to meet the optimum growth.