Xylo-Oligosaccharides Supplementation Affects Growth Performance,Non-Specific Immunity,Antioxidant Function and Anti-White Spot Syndrome Virus Capacity of Juvenile Litopenaeus vannamei

This experiment was aimed to study whether xylo-oligosaccharides( XOS) supplementation could affect non-specific immunity,antioxidant function and anti-white spot syndrome virus( WSSV) capacity of juvenile Litopenaeus vannamei. Eight hundred juvenile Litopenaeus vannamei with an initial body weight of( 0.67±0.02) g were randomly assigned to 4 groups with 4 replicates per group and 50 shrimps per replicate.Shrimps in the 4 groups were fed diets supplemented with 0( G0 group,as control group),200( G200group),400( G400 group) and 600 mg /kg( G600 group) XOS for 6 weeks,respectively. After the 6weeks' feeding trial,shrimps were injected with WSSV. The results showed that the weight gain rate( WGR),special gain rate( SGR),protein efficiency ratio( PER) and protein deposition rate( PDR) were significantly increased and the feed conversion ratio( FCR) was significantly decreased when adding200 mg /kg in the diet( P0.05). Dietary XOS could increase the total haemocyte count( THC),and that in G400 group was significantly higher than that in control group and G600 group( P 0.05). The activities of phenoloxidase( PO) and lysozyme( LZM) in serum and LZM in gill were significantly increased by adding XOS in the diet( P0.05). Compared with control group,the activities of superoxide dismutase( SOD) and peroxidase( POD) in serum and hepatopancreas and serum total antioxidant capacity( T-AOC) in G200 group were significantly increased( P 0.05),the hepatopancreas T-AOC in experimental groups was significantly increased( P0.05),and the activity of hepatopancreas anti-superoxide anion radical( Anti-O-2·) in G400 group was significantly increased( P 0. 05),while the hepatopancreas malondialdehyde( MDA) content in G400 group and the serum MDA content in experimental groups were significantly reduced( P0.05). After72 h of WSSV injection,the cumulated mortality rate( CMR) in experimental groups was significantly decreased compared with control group( P0.05),and the relative percentage survival( RPS) in G200,G400 and G600 groups was 15.2%,18.2% and 15.2%,respectively. In conclusion,suitable amount of XOS in the diet can improve growth performance,non-specific immunity,antioxidant function and anti-WSSV capacity of juvenile Litopenaeus vannamei.