本研究通过8周生长试验研究了饲喂果寡糖对奥尼罗非鱼Oreochromis aurea♂×O.nilotica♀肠道菌群、存活率及生产性能的影响.试验设计3组果寡糖水平(0、0.8及1.2g/kg),按每天4次饱食投喂初始重为5.55 g的奥尼罗非鱼,试验系统为淡水养殖系统,试验期间平均水温为28℃,罗非鱼养殖密度40尾/箱,每组3个重复.饲喂试验结束后,试验动物整体称重并测定形态学参数.从每个养殖单元随机取出3尾试验鱼,无菌条件下取肠道通过选择性培养基分别分析副溶血性弧菌Vibrio parahaemolyticus、嗜水气单胞菌 Aeromonas hydrophila、乳酸杆菌 Lactobacillus sp.及粪链球菌 Streptoccus faecalis 的数量.结果表明:随着饲喂果寡糖水平增加,奥尼罗非鱼末重(FBW,g)和特定生长率(SGR,%/d)均显著增加(P＜0.10);日摄食率(FI,g/(d·只)也增加(P＞0.10);饲料转化率和肝胰腺指数均降低(P＞0.10);而存活率(SR,%)、屠宰率(DCY,%)及丰满度(CF,g/cm3)则不受影响.所检测的全部罗非鱼肠道菌群数量随着饲喂果寡糖水平的上升呈增加状态(P＞0.10).本研究说明,饲料中添加果寡糖对奥尼罗非鱼生产性能、饲料转化效率及肠道菌群有一定改善作用,本研究推荐奥尼罗非鱼饲料中适宜果寡糖水平为1.2g/kg.%An 8-week feeding trial was conducted to investigate the effect of short-chain fructo-oligosaccharides (ScFOS, Profeed , 95%) on the intestinal microflora, mortality and growth performance of hybrid tilapia Oreochrotimes daily to triplicate groups of hybrid tilapia (40 fish/group, initial body weight (5.55 ± 0.02) g) reared in a flow-through system. At the end of the feeding trial, the animals were bulk weighed and various morphologic parameters were assessed. Intestinal samples from three individuals of each group were pooled in order to conduct the quantitative analysis of Vibrio parahaemolyticus , Aeromonas hydrophila , Lactobacillus sp., and Streptococcus faecalis by selected agar. The results showed that final body weight (FBW, g) and specific growth rate (SGR,%/d)were significantly improved with the increasing level of ScFOS in the diets for hybrid tilapia (P＜0.10), and daily index (HI, %) were decreased with the ascending dietary ScFOS content (P＞0.10). Survival rate (SR, %), C.V. of the final body weight (%), and condition factor (CF, g/cm3) were not affected by ScFOS (P＞0.10). All the intestinal bacteria tested showed a non-significant increase in hybrid tilapia (P＞0.10). The study indicates that dietary ScFOS may have beneficial effects on growth, feed conversion, intestinal microflora in tilapia. Based on our results, the optimal dietary ScFOS level should be 1.2 g/kg for hybrid tilapia.
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