The effects of Agaricus bisporus polysaccharides enriched diet on growth, nonspecific immunity and disease resistance in crayfish (Procambarus clarkii)

In order to accelerate the application of ABPs in shrimp and crab feed, we evaluated the effect of ABPs on the growth, non-specific immunity and disease resistance of crayfish. Crayfish (Procambarus clarkii) were randomly divided into six groups, the fed diets supplemented with different levels of ABPs: 0, 0.05, 0.15, 0.3, 0.45 and 0.6 g/kg. After 28 days of feeding, ABPs were found to significantly increase FBW and WG of crayfish. The addition of 0.15-0.6 g/kg of ABPs to the feed significantly increased the activities of ACP, AKP and T-SOD, decreased the activity of MDA enzymes in the hepatopancreas of crayfish. In the hemolymph, ABPs at 0.3-0.45 g/kg can significantly increase the activities of ACP, AKP, T-SOD and LZM enzymes, while the addition of 0.15 or 0.6 g/kg has no significant difference with the control group. The results of qPCR showed the addition of 0.15-0.6 g/kg ABPs to the feed could significantly up-regulate the expression levels of gpx, lec and hsp70 mRNA in the hepatopancreas (P < 0.05). Adding 0.15-0.6 g/kg of ABPs could up-regulate the expression of ctsb and lec gene in gills. In addition, the expression of alf was up-regulated in gills only when the addition amount of ABPs was 0.3 g/kg. While the expression of mtMnsod in gills was up-regulated when the addition amount was 0.3-0.6 g/ kg. Addition of 0.05-0.6 g/kg of ABPs reduced the mortality of crayfish infected by A.hydrophila. The above results indicated that the addition of ABPs could improve the growth, non-specific immunity and disease resistance of crayfish, and the addition of 0.3 g/kg and 0.45 g/kg of ABPs might be beneficial to the culture of crayfish.