饲料中添加低聚木糖对奥尼罗非鱼生长性能和血清生化指标的影响

摘要

本试验旨在研究低聚木糖(xylooligosaccharide)对奥尼罗非鱼(Oreochromis niloticus×O.aureus)生长性能和血清生化指标的影响.选取960尾初始均重为(5.09±0.12)g的奥尼罗非鱼,随机分为6组,每组设4个重复,每个重复40尾鱼.G0组为对照组,饲喂基础饲料；G200、G400、G600、G800和GI000组为添加组,分别饲喂在基础饲料中添加200、400、600、800和1 000 mg/kg低聚木糖的试验饲料.试验期为8周,每2周取样测定血清超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)、过氧化氢酶(CAT)活力和总蛋白(TP)含量,试验结束时计算生长指标.结果显示,除G200组外,各添加组罗非鱼的增重率均高于对照组,但未达到显著水平(P＞0.05)；各组罗非鱼的摄食量和存活率差异不显著(P＞0.05)；G800组蛋白质效率显著高于G200组(P＜0.05),而饲料系数则相反.罗非鱼体常规成分各组之间没有显著差异(P＞0.05).第4周时,各添加组的血清AKP、CAT活力和TP含量均高于对照组,其中G400组显著高于对照组(P＜0.05)；第6周时,G400组的血清SOD、AKP、CAT活力和TP含量均显著高于对照组(P＜0.05),第8周时,各添加组的血清SOD活力均显著高于对照组(P＜0.05).由此得出,在奥尼罗非鱼饲料中添加一定量的低聚木糖对生长性能和体常规成分的影响不显著,但对血清生化指标有显著影响,血清生化指标随时间变动呈现动态变化,其中以第6周时的血清SOD、AKP和CAT活力为指标,建议添加量为600～710mg/kg.%This experiment was conducted to investigate the effects of dietary xylooligosaccharides (XOS) on growth performance and serum biochemical indices of tilapia (Oreochromis niloticus x O. Aureus). A total of 960 fish with an average body weight of (5.09+0. 12) g were randomly divided into 6 groups with 4 replicates in each group and 40 fish per replicate. The fish in control group (GO group) were fed a basal diet, and those in other 5 groups (G200, G400, G600, G800 and G1000 groups) were fed the basal diet supplemented with 200, 400, 600, 800 and 1 000 mg/kg XOS, respectively. After 8 weeks feeding, weight gain rate (WGR) , feed intake (FI) , feed conversion ratio (FCR), protein efficiency ratio (PER) and survival rate ( SR) were measured. The activities of superoxide dismutase (SOD) , alkaline phosphatase ( AKP) and catalyse (CAT) , and total protein (TP) content in serum were determined every 2 weeks, respectively. The results showed that there was no significant difference in the WGR of fish among all groups (P >0. 05), however, fish fed diets supplemented with 400 to 1 000 mg/kg XOS had higher WGR than those fed the basal diet. FI and SR of fish in all groups were not significantly affected by the dietary XOS (P > 0. 05). PER in the G800 group was significantly higher than that in the G200 group (P <0. 05) , and FCR in the G800 group was significantly lower than that in the G200 group (P <0. 05). There was no significant difference in the body conventional components of tilapia (P >0.05). At the 4th week, serum AKP, CAT activities and TP content in the groups with the diets containing XOS were higher than those in the control group, and a significant difference was found between the G400 group and control group (P <0.05). At the 6th week, serum SOD, AKP, CAT activities and TP content in the G400 group were significantly higher than those in the control group (P <0.05). At the 8th week, serum SOD activity in the groups with the diets containing XOS was significantly higher than that in the control group (P <0. 05). The results suggest that supplementation of XOS into the diets show no significant effects on growth performance and body conventional components of the tilapia (Oreochromis niloticus x O. Aureus) , but the serum biochemical indices are significantly affected by XOS supplementation, and show a dynamic change with time. Based on the activities of serum SOD, AKP and CAT at the 6th week, the optimal dietary XOS supplemental level is 600 to 710 mg/kg.