饵料中添加益生菌对奥尼罗非鱼生长性能和肠道蛋白酶活性的影响

目的]研究在基础饵料中添加不同水平的复合益生菌对奥尼罗非鱼生长性能和肠道蛋白酶活性的影响,为益生菌在罗非鱼饵料中的应用提供理论依据.方法]将720尾奥尼罗非鱼种随机分成6组,每组3个重复,每个重复40尾鱼种,采用网箱养殖,分别在基础饵料中添加0、0.3%、0.4%、0.5%、0.6%和0.7%复合益生菌,饲养102 d后测定各组罗非鱼的生长性能指标和肠道蛋白酶活性,并建立曲线回归模型.结果]与对照组相比,添加复合益生菌试验组罗非鱼平均增重、增重率和特定生长率提高的最大幅度分别为11.98%、19.43%和6.99%,饵料系数最大降幅为9.77%,肠道蛋白酶活性提高的幅度为29.54%~49.81%.回归分析复合益生菌添加水平与罗非鱼平均增重、增重率、特定生长率、肠道蛋白酶活性、饵料系数的相关性,得知复合益生菌在罗非鱼基础饵料中的适宜添加量为0.40%~0.66%.结论]在基础饵料中添加适量(0.40%~0.66%)的复合益生菌可显著提高奥尼罗非鱼的生长速度和肠道蛋白酶活性,显著降低饵料系数,进而节约饵料成本、增加养殖效益.

Tilapia growth and intestinal protease activity analysis after compound probiotics addition in diet

【Objective】This research studied the growth performance and intestinal protease activities of Oreochromis niloticus × O. Aureus tilapia by adding different levels of composite probiotics in basal tilapia feed in order to provide theoretical references for future composite probiotics usage in tilapia’s diet. 【Method】Seven hundred and twenty tilapias were randomly divided into six treatments with three replicates per treatment and forty tilapias per replicate. Diets containing compound probiotics of 0， 0.3， 0.4， 0.5， 0.6， and 0.7% were fed to the tilapias under cage-culturing for 102 days， then the tilapia growth performance and intestinal protease activities were examined and the curvilinear regression model was established. 【Result】For tilapias in the composite probiotics treatment groups， the average weight gain， weight gain rate， and specific growth rate maximally increased by 11.98， 19.43， and 6.99%， the feed coefficient maximally decreased by 9.77% and the intestinal protease activities increased by 29.54-49.81% in comparison to the tested results of the control group. The regression analysis of corresponding relationships between compound probiotics addition levels and the average weight gain， weight gain rate， specific growth rate， intestinal protease activity， and feed coefficient of tilapia supported that the appropriate probiotics dosage in tilapia diet was 0.40-0.66%. 【Conclusion】Adding the appropriate amounts of composite probiotics （0.40-0.66%） in tilapia feed could effectively increase tilapia’s growth rate and intestinal protease activities and decrease the corresponding feed coefficients， thus saving feeding costs and improving breeding benefits.