Effects of dietary xylooligosaccharide on growth performance, enzyme activity and immunity of juvenile grass carp, Ctenopharyngodon idellus
Zhihao Zhang, Ming Chen, Shiwei Xie, Xianquan Chen, Yongjian Liu, Lixia Tian, Jin Niu
Abstract
An 8-week feeding trial was conducted to evaluate the effects of xylooligosaccharde (XOS) on growth, immunity and disease resistance of juvenile grass carp (Ctenopharyngodon idella). Fish (3.05 ± 0.01 g) were fed with diets containing XOS at levels of 0, 0.05 %, 0.1 %, 0.2 %, 0.4 % and 0.6 %. Results showed that the plasma triglyceride content was significantly lower in fish fed dietary 0.05 % and 0.1 % XOS compared to the control group (P < 0.05). Fish fed dietary 0.05 %, 0.1 % and 0.2 % XOS displayed significantly higher final body weight, weight gain and specific growth rate compared to the control group (P < 0.05). Fish fed 0.1 % XOS had significantly lower plasma malondialdehyde content and higher lysozyme activity than the control group (P < 0.05). XOS did not affect liver superoxide dismutase activity and glutathione content, but significantly reduced MDA content (0.4 % and 0.6 %) (P < 0.05). After Aeromonas hydrophila challenge, 0.1 % XOS significantly improved the survival rate of C. idella compared to that of the control diet (P < 0.05). Thus, the most suitable dietary supplementation level of XOS is 0.1 % for C. idella.