Dietary chitosan moderates the growth rate, antioxidant activity, immunity, intestinal morphology and resistance against Aeromonas hydrophila of juvenile hybrid sturgeon (Acipenser baerii? x Acipenser schrenckii?)

This study investigated the effects of dietary chitosan on growth, antioxidant, immunity, intestinal morphology and resistance against Aeromonas hydrophila of hybrid sturgeon (Acipenser baerii female x Acipenser schrenckii male). Sturgeons (18.18 +/- 0.08 g) were randomly divided into four groups, fed with chitosan-supplemented diets for 8 weeks and then infected with A. hydrophila. The results showed significant differences of body weight gain, specific growth rate and feed conversion ratio in sturgeon fed chitosan and control diets. The oral administration of chitosan significantly increased the acid phosphatase, alkaline phosphatase, lysozyme, myeloperoxidase, su-peroxide dismutase, glutathione peroxidase and catalase activities, as well as the complement 3 and 4 contents and disease resistance against A. hydrophila. Moreover, enhancement of muscular thickness and goblet cells in mid intestine and increase of muscular thickness and villus height in spiral valve were observed in the chitosan supplemented groups. In addition, dietary chitosan-supplemented diets mitigated the changes of antioxidant and immune activity induced by A. hydrophila challenge, as well as prevented fish from bacterial invasion. The optimal dose was 3.00 g chitosan/kg diet for hybrid sturgeon.

Automated summary

This study explored the effects of dietary chitosan on the growth, antioxidant activity, immunity, intestinal morphology, and resistance to Aeromonas hydrophila in hybrid sturgeon. The results indicated that chitosan supplementation significantly improved the growth performance, disease resistance, and intestinal health of the sturgeon. The optimum dosage of chitosan was 3.00 g/kg diet.