Effects of Alpinia officinarum stems and leaves extract on growth performance, non-specific immunity, and intestinal microflora of Litopenaeus vannamei

This study was to investigate the effects of Alpinia officinarum Hance stems and leaves extract (AOE) on the growth, non-specific immunity, intestinal microflora of shrimp (Litopenaeus vannamei). A total of 540 juvenile L. vannamei (2.69 +/- 0.03 g) were randomly divided into six groups, and feed experiment with diet supplement of 0 g/kg (CG), 0.1 g/kg (AO-1), 0.2 g/kg (AO-2), 0.3 g/kg (AO-3), 0.5 g/kg (AO-4) and 0.7 g/kg(AO-5) AOE was carried out for 8 weeks, respectively. Compared with the control group (CG), the WGR and SGR of the AO-1, AO3, and AO-4 groups were significantly increased. Crude protein content in the muscle of L. vannamei in AO-2 was significantly increased, while the water content was significantly decreased. The crude lipid content of each extract group was significantly decreased. Compared with the control group, activities of GSH-Px, SOD, and TAOC in the cell-free hemolymph of AO-3 group were significantly enhanced, and the MDA content of each extract group was significantly decreased. Activities of CAT, SOD, and T-AOC in the hepatopancreas of AO-2 group were significantly increased. Gene expression levels of lvcat, lvgsh-px, and lvmn-sod in AO-3 group were obviously higher than those in the control group, while lvpropo expression was dramatically higher in AO-2 and AO-3 groups. Moreover, AOE addition in feed changed the composition and species abundance of intestinal microflora of L. vannamei at phylum and genus levels. Through alpha diversity analysis, the biodiversity of the flora was improved, while beta diversity analysis changed the similarity of the flora between the control and addition groups. Therefore, addition of 0.2-0.3 g/kg AOE could improve the growth, immunity and optimize the composition of intestinal microorganisms of L. vannamei.