Modulation of growth performance, non-specific immunity, intestinal morphology, the response to hypoxia stress and resistance to Aeromonas hydrophila of grass carp (Ctenopharyngodon idella) by dietary supplementation of a multi-strain probiotic.

摘要: Abstract The present study was conducted to evaluate a multi-strain probiotic (MP) on growth performance, immune and antioxidant function, response hypoxia stress resistance Aeromonas hydrophila of grass carp (Ctenopharyngodon idella). Based the viable cell counts aerobic Bacillus spp., six experimental diets with MP supplemented at 0, 0.34, 1.68, 3.36, 6.72, 10.1 g kg−1 were formulated 900 juveniles (7.30 ± 0.01 g) equally distributed into 30 aquaria respective diet for 60 days. Results showed that fish 0.34–1.68 g kg−1 had better feed utilization. Further, plasma total protein, albumin high-density lipoprotein remarkably increased dietary >1.68 g kg−1. Dietary supplementation 6.72–10.1 g kg−1 strikingly elevated myeloperoxidase activity complement C3 content. For 1.68 6.72–10.1 g kg−1, their liver malondialdehyde glutathione peroxidase declined promoted. After stress, 3.36–6.72 g kg−1 significantly higher respiratory burst activity. Challenge test by A. confirmed protection effects through decreased cumulative mortality rates. intestinal histomorphology enzymatic analyses, 1.68 g kg−1 displayed villi height, goblet cells alkaline phosphatase In conclusion, could promote growth, morphology capacity, while enhancing host immunity requires dosages MP. Broken-line analysis weight gain revealed 1.34 g kg−1 is optimum dosage carp.